Co-reporter:Ping Tan, Guanna Li, Ruiqi Fang, Liyu Chen, Rafael Luque, and Yingwei Li
ACS Catalysis April 7, 2017 Volume 7(Issue 4) pp:2948-2948
Publication Date(Web):March 14, 2017
DOI:10.1021/acscatal.6b02853
Metal/metal oxide nanoparticles with controllable size and shape are of importance to tailor the catalytic performances of metal nanoparticles. However, a facile synthesis of supported monodisperse metal/oxide polyhedra in the absence of capping agents remains a significant challenge, especially at high metal loadings. In this work, a surfactant-free MOF (metal–organic framework) thermolysis strategy is developed for the synthesis of monodisperse ferrite octahedral nanocrystals with uniform composition for the first time. The achievement of our synthesis relies on the use of CO as directing agent that may control the growth rate of specific facets at the solid/gas interface and, subsequently, the shape of the resultant metal oxide nanostructures. As-prepared octahedral ferrite materials exhibited an interesting shape-dependent catalytic performance in 5-hydroxymethylfurfural (HMF) oxidation, achieving significantly improved activity and selectivity, compared to those synthesized under a pure inert atmosphere. Density functional theory (DFT) calculations suggest a relatively weak interaction between 2,5-diformylfuran (DFF) and the catalyst that is highly beneficial for product desorption, avoiding the overoxidation reactions that occur on the catalyst surface to some extent and partially contributing to the high DFF selectivity.Keywords: biomass; ferrite; heterogeneous catalysis; metal−organic frameworks; nanocrystals;
Co-reporter:Liyu Chen;Weihao Huang;Xiujun Wang;Zhijie Chen;Xianfeng Yang;Rafael Luque
Chemical Communications 2017 vol. 53(Issue 6) pp:1184-1187
Publication Date(Web):2017/01/17
DOI:10.1039/C6CC09270E
A series of crown-jewel Pd-based bimetallic nanostructures with tunable composition are fabricated inside the pores of an MOF via a hydride-induced-reduction strategy, exhibiting high activity and stability in the hydrogenation of nitrobenzene.
Co-reporter:Liyu Chen;Rafael Luque
Chemical Society Reviews 2017 vol. 46(Issue 15) pp:4614-4630
Publication Date(Web):2017/07/31
DOI:10.1039/C6CS00537C
The controllable encapsulation of nanoentities (such as metal nanoparticles, quantum dots, polyoxometalates, organic and metallorganic molecules, biomacromolecules, and metal–organic polyhedra) into metal–organic frameworks (MOFs) to form composite materials has attracted significant research interest in a variety of fields. These composite materials not only exhibit the properties of both the nanoentities and the MOFs but also display unique and synergistic functionalities. Tuning the sizes, compositions, and shapes of nanoentities encapsulated in MOFs enables the final composites to exhibit superior performance to those of the separate constituents for various applications. In this tutorial review article, we summarized the state-of-the-art development of MOFs containing encapsulated tunable nanoentities, with special emphasis on the preparation and synergistic properties of these composites.
Co-reporter:Huirong Chen;Kui Shen;Junying Chen;Xiaodong Chen
Journal of Materials Chemistry A 2017 vol. 5(Issue 20) pp:9937-9945
Publication Date(Web):2017/05/23
DOI:10.1039/C7TA02184D
Semiconducting metal oxides have been considered as effective photocatalysts for the degradation of organic pollutants to decolorize contaminated water. However, the poor performance and difficulty in recycling greatly hinder their practical application. Herein, we designed and fabricated, for the first time, a novel ZnO@C–N–Co core–shell nanocomposite towards efficient and recyclable photocatalysis by directly pyrolyzing a hollow Zn/Co–ZIF matrix consisting of a ZIF-8 shell with some Co–ZIF nanoplates inside the hollow cavity. It was demonstrated that the ZIF-8-shell-derived ZnO nanoparticles could spontaneously agglomerate and move to the hollow cavity while the internal Co NPs transferred inversely to the ligand-derived N–C shell at suitable pyrolysis temperature, resulting in the unique ZnO@C–N–Co core–shell structure. This unique nanostructure possessed the following superior properties: (1) a core–shell structure may make the intermediate ZnO much more stable during the reaction; (2) a porous carbon shell can not only provide a high BET specific area and thus high adsorption capability for reactants, but can also inhibit the recombination of photogenerated electrons and holes; (3) the embedded Co NPs were able to provide richer electron traps that further suppress the recombination of electrons and holes. As exemplified for the degradation of methyl orange, the ZnO@C–N–Co showed a significantly improved performance and excellent recyclability due to the highly synergistic effects between the C–N–Co shell and the robust ZnO. This strategy for the synthesis of MOF-derived core–shell nanomaterials could offer prospects for developing highly efficient photocatalysts.
Co-reporter:Kui Shen;Ning Wang;Xiaodong Chen;Zhaohui Chen;Junying Chen;Weizhong Qian;Fei Wei
Catalysis Science & Technology (2011-Present) 2017 vol. 7(Issue 21) pp:5143-5153
Publication Date(Web):2017/10/30
DOI:10.1039/C7CY01647F
We reported a general seed-induced strategy for the synthesis of both meso/macroporous ZSM-5 and ZSM-11 (denoted as N-ZSM-5 and N-ZSM-11, respectively) under additive-free, low template/SiO2 ratio (from 0.011 to 0.0014) and seed-assisted hydrothermal conditions. It was found that both N-ZSM-5 and N-ZSM-11 were primarily composed of 20–50 nm oriented nanorods, which showed excellent physicochemical properties, such as high crystallinity, large surface area, auxiliary meso/macroporous structures, and uniform size. When being used in the methanol-to-aromatics reaction (MTA), both Zn/N-ZSM-5 and Zn/N-ZSM-11 exhibited high catalytic efficiencies, as reflected by their far longer lifetimes and higher selectivities for total aromatics than conventional Zn/ZSM-5 and Zn/ZSM-11, due to their unique meso/macroporous structure and ultra-small crystal size that resulted in substantial improvements in the mass-transport properties. This seed-induced strategy inspires new ideas for the design and fabrication of oriented nanorod-assembled hierarchical zeolites with lower cost and good catalytic performance.
Co-reporter:Jianmin Chen;Junying Chen
Journal of Materials Chemistry A 2017 vol. 5(Issue 46) pp:24116-24125
Publication Date(Web):2017/11/28
DOI:10.1039/C7TA07587A
Hydrogen production through water splitting under visible-light irradiation is considered as an ideal process to convert solar energy into chemical energy. In this work, we report the rational design of a new kind of visible-light photocatalyst, hollow ZnCdS rhombic dodecahedral cages, fabricated via simple sulfurization and cation-exchange using zeolitic-imidazolate-framework-8 (ZIF-8) as the single precursor. The hollow cages and mesoporous structures can endow Zn1−xCdxS solid solutions with significantly improved visible-light utilization and charge carrier separation and transfer. In addition, the BET surface areas of hollow ZnCdS cages were also significantly enhanced with the introduction of Cd as compared to those of ZnS cages, benefitting the provision of abundant exposed active sites and decrease of the charge transport distance. Moreover, suitable band matching and strong electron coupling in these solid solutions could be simultaneously achieved via ion-exchange, featuring the balance between the light absorption ability and the potential of the conduction band of the Zn1−xCdxS photocatalysts. Consequently, the hollow Zn0.6Cd0.4S cage material exhibited the highest hydrogen production rate of 5.68 mmol h−1 g−1 under cocatalyst-free and visible-light irradiation (λ > 420 nm) conditions. Furthermore, these hollow ZnCdS cages showed excellent long-term stability, maintaining high photocatalytic activity for hydrogen evolution over a number of cycles. We believe that this facile strategy for developing highly efficient ZnCdS photocatalysts from MOFs could be extended to the synthesis of other metal hollow cages for a variety of advanced applications.
Co-reporter:Zhijie Chen, Junying Chen, Yingwei Li
Chinese Journal of Catalysis 2017 Volume 38, Issue 7(Volume 38, Issue 7) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/S1872-2067(17)62852-3
Metal–organic-framework (MOF)-based materials with novel physicochemical properties have emerged as promising catalysts for various hydrogenation reactions. In addition to metal clusters and multifunctional organic ligands, MOF-based catalysts can incorporate other functional species, and thus provide various active sites for hydrogenation processes. The structural properties of the catalysts play significant roles in enhancing the interactions among the reactants, products, and catalytic sites, which can be rationally designed. Because of the synergistic effects between the active sites and the structural properties, MOF-based catalysts can achieve higher activities and selectivities in hydrogenation reactions than can be obtained using traditional heterogeneous catalysts. This review provides an overview of recent developments in MOF-based catalysts in the hydrogenation of alkenes, alkynes, nitroarenes, cinnamaldehyde, furfural, benzene, and other compounds. Strategies for improving the catalytic performances of MOF-based catalysts are discussed as well as the different active sites and structural properties of the catalysts.This review summarizes recent progress in metal–organic–framework-based catalysts in various hydrogenation reactions, including hydrogenation of alkenes, alkynes, nitroarenes, cinnamaldehyde, furfural, benzene, and other compounds.Download high-res image (71KB)Download full-size image
Co-reporter:Ruiqi Fang;Rafael Luque
Green Chemistry (1999-Present) 2017 vol. 19(Issue 3) pp:647-655
Publication Date(Web):2017/02/06
DOI:10.1039/C6GC02018F
Aerobic oxidation of carbohydrate-derived 5-hydroxymethylfurfural (HMF) into high added-value 2,5-diformylfuran (DFF) has attracted much attention in recent years. However, the direct synthesis of DFF from cheap and abundant carbohydrates via HMF as an intermediate through a one-pot process is highly desirable but challenging. In this work, we have developed a highly efficient and recyclable non-noble heterogeneous catalyst for one-pot conversion of fructose into DFF with extremely high yields (>99%). The catalyst was prepared by a simple pyrolysis method using Fe-based metal–organic frameworks (MOF) as a template and sulfur powder as a dopant. The pyrolysis of the MOF template under interactions of Ostwald ripening and Kirkendall effects led to the formation of uniform octahedral Fe3O4 nanoparticles with exposed (111) crystal facets highly dispersed on sulfur doped carbon. The superior selectivity to DFF over the designed Fe-based catalyst is related to the low adsorption energy of DFF on the support as well as the existence of non-oxidized sulfur that makes the catalytic system less oxidative.
Co-reporter:Xuan Qiu; Wei Zhong; Cuihua Bai
Journal of the American Chemical Society 2016 Volume 138(Issue 4) pp:1138-1141
Publication Date(Web):January 20, 2016
DOI:10.1021/jacs.5b12189
A new and efficient hydrophilicity-directed approach (HDA) is developed to encapsulate large guest molecules beyond the aperture size limitation in the nanospace of metal–organic frameworks (MOFs), as exemplified by the self-assembly of a metal–organic polyhedral (MOP) M6L4 into MIL-101. This strategy is based on the different hydrophilicities between inner and outer surfaces of the preformed MOF that may direct the self-assembly of the MOP in the MOF pores by using a two-solvent system. Importantly, as the MOP guest molecule is larger than the MOF aperture size, aggregation and leaching are effectively prevented, endowing the encapsulated MOP with significantly enhanced reactivity and stability in the catalytic transformations as compared to the pristine MOP.
Co-reporter:Cuihua Bai, Aiqin Li, Xianfang Yao, Hongli Liu and Yingwei Li
Green Chemistry 2016 vol. 18(Issue 4) pp:1061-1069
Publication Date(Web):02 Nov 2015
DOI:10.1039/C5GC02082D
A simple and highly efficient nanostructured catalyst system comprising magnetic Co nanoparticles stabilized by N-doped carbon composite (Co/C–N) was synthesized by one-pot thermal decomposition of a Co-containing MOF. The catalysts were characterized by temperature programmed desorption (TPD), N2 physical adsorption, powder X-ray diffraction (PXRD), Raman spectroscopy, transmission electron microscopy (TEM), scanning electronic microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The catalytic activity of Co/C–N materials was investigated in the selective aerobic oxidation of alcohols in neat water under an atmospheric pressure of air and base-free conditions. As compared to those prepared by traditional impregnation methods, Co/C–N exhibited an efficient performance with significantly improved catalytic activities. Besides conferring high activity and selectivity to the target products, the proposed catalytic system featured a broad substrate scope for both aryl and alkyl alcohols. Furthermore, the magnetically recoverable Co/C–N catalyst could be easily separated from the reaction system by using an external magnetic field and reused at least five times without any significant loss in catalytic efficiency under the investigated conditions.
Co-reporter:Liyu Chen, Lei Zhang, Zhijie Chen, Hongli Liu, Rafael Luque and Yingwei Li
Chemical Science 2016 vol. 7(Issue 9) pp:6015-6020
Publication Date(Web):31 May 2016
DOI:10.1039/C6SC01659F
Metal nanoparticles (NPs) encapsulated in hollow nanostructures hold great promise for a variety of applications. Herein, we demonstrate a new concept where covalent organic frameworks (COFs) doped with metal cations can be readily used as novel precursors for the in situ encapsulation of metal NPs into N doped hollow carbon spheres (NHCS) through a controlled carbonization process. The obtained Pd@NHCS composites show a significantly enhanced catalytic activity and selectivity in the hydrogenation of nitrobenzene in ethanol and oxidation of cinnamyl alcohol compared with that of the conventional Pd/N–C and commercial Pd/C catalysts. The excellent catalytic performance should be related to the synergism of the porous hollow spheric structure, highly dispersed Pd NPs, and uniform distribution of N dopants on the materials. We believe that this newly developed methodology could be extended to the synthesis of other metal NPs@NHCS composites for a variety of advanced applications.
Co-reporter:Ruiqi Fang, Rafael Luque and Yingwei Li
Green Chemistry 2016 vol. 18(Issue 10) pp:3152-3157
Publication Date(Web):11 Feb 2016
DOI:10.1039/C5GC03051J
The conversion of renewable biomass resources into fuels, polymers, and fine chemicals provides solutions for the growing shortage of fossil resources, environmental pollution and a possible crisis in energy supply. 5-Hydroxymethylfurfural (HMF) is an important biomass-derived platform chemical, and its selective oxidation to multifunctional molecules such as 2,5-diformylfuran (DFF) remains an ongoing challenge. The present work reports a sustainable, cost-effective, and highly efficient catalytic system for directly transforming HMF to DFF that afforded >99% DFF yield under relatively mild reaction conditions. The reaction was catalyzed by naturally abundant and non-noble Fe–Co based catalysts derived from a metal–organic framework (MIL-45b) employed as a sacrificial template. The unique hollow structure of the nanomaterial favored the adsorption of HMF and quick desorption of the formed DFF from the catalyst surface, leading to a high yield of DFF that could be comparable to that obtained with noble metal catalysts under similar conditions. The catalyst could also be easily recovered and reused up to six runs without any significant loss in reactivity.
Co-reporter:Kui Shen, Xiaodong Chen, Junying Chen, and Yingwei Li
ACS Catalysis 2016 Volume 6(Issue 9) pp:5887
Publication Date(Web):July 26, 2016
DOI:10.1021/acscatal.6b01222
Carbon-based nanomaterials have been widely used as catalysts or catalyst supports in the chemical industry or for energy or environmental applications due to their fascinating properties. High surface areas, tunable porosity, and functionalization are considered to be crucial to enhance the catalytic performance of carbon-based materials. Recently, the newly emerging metal–organic frameworks (MOFs) built from metal ions and polyfunctional organic ligands have proved to be promising self-sacrificing templates and precursors for preparing various carbon-based nanomaterials, benefiting from their high BET surface areas, abundant metal/organic species, large pore volumes, and extraordinary tunability of structures and compositions. In comparison with other carbon-based catalysts, MOF-derived carbon-based nanomaterials have great advantages in terms of tailorable morphologies and hierarchical porosity and easy functionalization with other heteroatoms and metal/metal oxides, which make them highly efficient as catalysts directly or as catalyst supports for numerous important reactions. In this perspective, we intend to give readers a survey of the research advances in the use of MOFs as self-sacrificing templates and precursors to prepare carbon-based nanomaterials, mainly including heteroatom-doped porous carbons and metal/metal oxide decorated porous carbons for applications as catalysts in energy and environment-related electrocatalysis and traditional heterogeneous catalysis. Finally, some perspectives are provided for future developments and directions of MOF-derived carbon-based materials for catalysis.Keywords: carbon; catalysis; metal−organic frameworks; nanomaterials; pyrolysis
Co-reporter:Liyu Chen, Binbin Huang, Xuan Qiu, Xi Wang, Rafael Luque and Yingwei Li
Chemical Science 2016 vol. 7(Issue 1) pp:228-233
Publication Date(Web):23 Sep 2015
DOI:10.1039/C5SC02925B
The possibility of using inner cavities within metal–organic frameworks (MOFs) as templates for the fabrication of tiny metal nanoparticles (NPs) was attempted in this work. An unprecedented design of Pd@Ag core–shell NPs on MOFs via a seed mediated growth strategy is reported and attributed to the presence of activated physisorbed hydrogen atoms on embedded Pd NPs as reducing agents to selectively direct the deposition of Ag onto Pd while minimizing the Ag self-nucleation. The obtained Pd@Ag core–shell NPs exhibited a significant increase in selectivity in the partial hydrogenation of phenylacetylene as compared to their monometallic counterparts, due to the surface dilution and electron modification of the surface Pd sites by Ag deposition. Pd@Ag NPs also possessed an unprecedented high stability and recyclability in the catalytic reactions, related to the nano-confinement effect and the strong metal–support interaction offered by the MOF framework.
Co-reporter:Xi Wang and Yingwei Li
Journal of Materials Chemistry A 2016 vol. 4(Issue 14) pp:5247-5257
Publication Date(Web):09 Mar 2016
DOI:10.1039/C6TA00324A
Metal-free nanocarbon catalysts have attracted much attention in recent years for their advantages of corrosion resistance, no heavy metal pollution and environmental friendliness as compared to metal-based catalysts. However, a facile preparation of heteroatom doped mesoporous carbon with a high catalytic efficiency is challenging. Here we report the development of a new kind of metal-free catalyst comprised of highly graphitized N-doped nanoporous carbons from direct carbonization of metal–organic frameworks. After metal etching, large specific surface areas and pore volumes, as well as high contents of sp2-bonded carbons are realized in the obtained carbons at the same time. As metal-free catalysts, these nitrogen-doped carbon materials exhibit excellent catalytic performances and robust stability in a series of oxidation reactions including aerobic oxidation of cyclohexane and toluene as well as oxidative coupling of amines. Systematic characterizations suggest that the accessible mesopores generated by chemical etching, and the homogeneous distribution of doped graphitic-type nitrogen should be responsible for the unprecedented performance of these carbon catalysts.
Co-reporter:Jilan Long, Kui Shen, Liang Chen and Yingwei Li
Journal of Materials Chemistry A 2016 vol. 4(Issue 26) pp:10254-10262
Publication Date(Web):02 Jun 2016
DOI:10.1039/C6TA00157B
Transition metal NPs and their alloy NPs have attracted significant attention due to their low cost and potential to replace noble-metal-based catalysts in many reaction systems; however, major challenges are still encountered when exploring cost-effective and scaleable strategies to prepare and attach them with optimal supports for maximizing their catalytic efficiency. Here, we report a facile and repeatable route to synthesize transition metal based nano-catalysts by first developing a series of new and novel N-donor multimetallic M–M′-MOFs [(M–M′(1,4-bdc)2(dabco)]·4DMF·1/2H2O, M/M′ = Co, Ni, Cu) by a facile mixed-metal approach and then directly pyrolyzing these hetero-nuclear MOFs under inert gas. In the pyrolysis process, the transition metal ions (two of Co, Ni, and Co) of M–M′-MOFs could be transformed into transition alloy nanoparticles while the surrounding N-containing ligands were polymerized to N-doped graphitic carbon, resulting in highly dispersed M/M′ alloy NPs embedded in the N-doped carbon matrix. The detailed characterization results revealed that the metal elements including Co, Ni, and Cu were uniformly distributed in every individual alloy NP and there existed an obvious synergetic activation of different transition metals and strong coordination interactions between metals of alloy NPs and N atoms. When being used in the transfer hydrogenation of nitriles in the absence of basic additives, the optimal Co–Ni(3:1)@C–N showed the best catalytic performance with 100% conversion of benzonitrile and over 98% yield for the desired product, which was almost 5 times more active than its monometallic counterparts. We believe that this MOF-templating strategy provides a facile and controllable route for the preparation of nanocatalysts based on transition metal NPs with high transfer hydrogenation performance.
Co-reporter:Xianfang Yao, Cuihua Bai, Junying Chen and Yingwei Li
RSC Advances 2016 vol. 6(Issue 32) pp:26921-26928
Publication Date(Web):08 Mar 2016
DOI:10.1039/C6RA01617K
A simple and highly efficient synthesis strategy for the green oxidation of alcohols to corresponding carbonyl products is developed using a heterogeneous non-noble magnetic Fe3O4@C catalyst. The magnetic nanocomposites were prepared by one-pot thermal decomposition of a Fe-containing MOF and fully characterized by powder X-ray diffraction (PXRD), N2 physical adsorption, atomic absorption spectroscopy (AAS), element analysis, scanning electronic microscopy (SEM), and transmission electron microscopy (TEM). The catalytic activities of Fe3O4@C materials were investigated in the selective oxidation of alcohols in neat water using hydrogen peroxide as a green oxidant under base-free conditions. Besides the high activity and selectivity to the target products, the proposed catalytic system features a broad substrate scope for both aryl and alkyl alcohols. Moreover, the magnetically catalyst could be easily separated by using an external magnetic field and reused for at least four times without significant loss in catalytic efficiency under the investigated conditions.
Co-reporter:Dr. Hongli Liu;Lina Chang;Liyu Chen ; Yingwei Li
ChemCatChem 2016 Volume 8( Issue 5) pp:946-951
Publication Date(Web):
DOI:10.1002/cctc.201501256
Abstract
The encapsulation of metal nanoparticles (MNPs) within metal–organic frameworks (MOFs) to form core–shell structural nanocomposites is one of the most promising methods to enhance the durability and selectivity of MOF-supported metal catalysts. However, it is still a challenge to fully encapsulate tiny MNPs inside MOFs. Herein, we report a facile and general strategy to coat MOFs on the surface of Pt/MOFs by direct homoepitaxial growth. The obtained Pt/MOFs@MOFs nanocomposites retained the intrinsic properties (e.g., crystalline structure, pore texture, and surface area) of Pt/MOFs. Strikingly, the MOF-coated materials exhibited a significantly enhanced chemoselectivity compared to the uncoated materials, for example, in the hydrogenation of cinnamaldehyde, the selectivity to cinnamyl alcohol through C=O hydrogenation was improved from 55 to 96 % at complete conversions of cinnamaldehyde. Moreover, Pt/MOFs@MOFs can be recycled without any remarkable loss in both activity and selectivity. The enhanced catalytic selectivity and stability of MNPs/MOFs could be related to the synergetic effects of the electron donation and nanoconfinement offered by the surrounding MOF networks.
Co-reporter:Junying Chen
The Chemical Record 2016 Volume 16( Issue 3) pp:1456-1476
Publication Date(Web):
DOI:10.1002/tcr.201500304
Co-reporter:Wei Zhong, Hongli Liu, Cuihua Bai, Shijun Liao, and Yingwei Li
ACS Catalysis 2015 Volume 5(Issue 3) pp:1850
Publication Date(Web):February 12, 2015
DOI:10.1021/cs502101c
The direct oxidation of alcohols to esters with molecular oxygen is an attractive and crucial process for the synthesis of fine chemicals. To date, the heterogeneous catalyst systems that have been identified are based on noble metals or have required the addition of base additives. Here, we show that Co nanoparticles embedded in nitrogen-doped graphite catalyze the aerobic oxidation of alcohols to esters at room temperature under base-free and atmospheric conditions. Our Co@C-N catalytic system features a broad substrate scope for aromatic and aliphatic alcohols as well as diols, giving their corresponding esters in good to excellent yields. This apparently environmentally benign process provides a new strategy with which to achieve selective oxidation of alcohols.Keywords: alcohols; cobalt; heterogeneous catalysis; metal−organic frameworks; oxidation
Co-reporter:Ruiqi Fang, Hongli Liu, Rafael Luque and Yingwei Li
Green Chemistry 2015 vol. 17(Issue 8) pp:4183-4188
Publication Date(Web):09 Jul 2015
DOI:10.1039/C5GC01462J
The selective hydrogenation of furfural into cyclopentanone is an attractive transformation to advance in the sustainable synthesis of important chemicals from biomass. A supported Ru nanoparticle catalyst on an acidic MOF material (Ru/MIL-101) was designed for the highly active and selective conversion of furfural to cyclopentanone in aqueous media. Complete conversion of furfural with a selectivity higher than 96% was achieved within 2.5 h at 160 °C and 4.0 MPa H2 pressure.
Co-reporter:Cuihua Bai, Xianfang Yao, and Yingwei Li
ACS Catalysis 2015 Volume 5(Issue 2) pp:884
Publication Date(Web):December 23, 2014
DOI:10.1021/cs501822r
A novel synthesis strategy for amides by oxidative amidation of aldehydes is developed using a heterogeneous Co-based catalyst. The Co composite was prepared by simple pyrolysis of a Co-containing MOF, to obtain well-dispersed Co nanoparticles enclosed by carbonized organic ligands. The catalysts were characterized by powder X-ray diffraction (PXRD), N2 physical adsorption, atomic absorption spectroscopy (AAS), transmission electron microscopy (TEM), scanning electronic microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The small Co nanoparticles embedded in the N-doped carbons were highly dispersed with an average size of ca. 7 nm. The Co@C-N materials exhibited significantly enhanced catalytic activity in the oxidative amidation of aldehydes in comparison to those of commercial sources. A series of amides can be easily obtained in good to excellent yields. It was found that the reaction proceeded via radicals under mild conditions, and the carbonyl group in the amide product was from the aldehyde. Moreover, the catalyst could be easily separated by using an external magnetic field and reused several times without significant loss in catalytic efficiency under the investigated conditions.Keywords: aldehydes; amides; cobalt; heterogeneous catalysis; metal−organic frameworks; nanoparticles
Co-reporter:Kui Shen, Liang Chen, Jilan Long, Wei Zhong, and Yingwei Li
ACS Catalysis 2015 Volume 5(Issue 9) pp:5264
Publication Date(Web):July 30, 2015
DOI:10.1021/acscatal.5b00998
Although MOFs supporting noble metal nanoparticles (NPs) have been widely used in heterogeneous catalysis, they are still limited in catalytic efficiency on a per-noble-metal-atom basis. Here we developed a MOFs-templated strategy to non-noble metal @noble metal core–shell nanocatalysts, which could far surpass the traditional MOFs supporting noble NPs in catalytic properties, by using MOFs-derived metal NPs as sacrificial templates to reduce noble metal ions via galvanic replacement reaction. As a model system, Co@Pd core–shell NPs embedded in the N-doped carbon matrix (Co@Pd/NC) were synthesized with an average size of ca. 9.4 nm and a ultrathin Pd shell by using ZIF-67 and Pd(NO3)2 as the precursor and Pd source, respectively. The highly exposed Pd atom on Co nanoparticles made it an attractive catalyst with high efficiency. When being used in the hydrogenation of nitrobenzene, the Co@Pd/NC exhibited an unprecedented high activity over Pd-based catalysts, yielding 98% conversion after 45 min reaction, which was far more active than the pristine ZIF-67 and MIL-101 supporting Pd NPs (with 40% and 3% conversion after 90 min reaction, respectively) under identical conditions, suggesting its overwhelmingly better performance than MOFs supporting noble NPs. We anticipated that this strategy would form the basis for developing a new class of MOF-templated core–shell nanocatalyst with potential applications in numerous catalytic reactions.Keywords: core−shell structure; heterogeneous catalysis; metal−organic frameworks; nanoparticles; noble metal
Co-reporter:Hongli Liu, Lina Chang, Liyu Chen and Yingwei Li
Journal of Materials Chemistry A 2015 vol. 3(Issue 15) pp:8028-8033
Publication Date(Web):11 Mar 2015
DOI:10.1039/C5TA00030K
The encapsulation of metal nanoparticles (MNPs) into metal–organic frameworks has generated recent research because of the promising novel physical and chemical properties originating from synergetic interactions between MNPs and MOFs. However, the development of a facile one-step approach for the incorporation of tiny MNPs within MOFs without additional stabilizing agents and reductants remains a great challenge. Herein, we report a new and general synthesis strategy for MNPs@MOFs that allows preferential self-assembly of MOFs around the in situ formed MNP surface by directly mixing both the reactive metal (e.g., H2PtCl6) and MOF precursors in DMF. This in situ one-step assembly approach is applicable to various MOFs, affording well-defined Pt@MOF composites with highly dispersed naked Pt NPs in narrow diameter distribution. The resulting Pt@MOF nanocomposites exhibit excellent stability, significantly enhanced catalytic activity and selectivity as compared to the commercial Pt/C in liquid-phase aerobic oxidation of alcohols.
Co-reporter:Liyu Chen, Xiaodong Chen, Hongli Liu, Cuihua Bai and Yingwei Li
Journal of Materials Chemistry A 2015 vol. 3(Issue 29) pp:15259-15264
Publication Date(Web):17 Jun 2015
DOI:10.1039/C5TA02860D
The control over the size and location of metal nanoparticles (MNPs) within metal–organic frameworks (MOFs) is achieved in one step through a cooperative in situ metal precursor incorporation and on-site moderate reduction process, which is operated by a temperature control program. The choice of operation temperatures is based on the MOF assembly temperature (T1), and an elevated temperature (T2) to elicit the reducibility of DMF solvent to fabricate MNPs. Such a rational design could effectively introduce metal precursors into the pores of MOFs and on-site moderately reduce the embedded metal ions to generate tiny MNPs by the penetrated DMF, which could not be achieved by a quick heating process. The proposed methodology has been successfully applied to the one-step fabrication of ultrafine Pd NPs selectively encapsulated inside the pores of UiO-67 without any external reducing agents. The obtained Pd-in-UiO-67 shows superior catalytic activity and selectivity in the hydrogenation of styrene even at room temperature and atmospheric pressure of H2.
Co-reporter:Xiaofang Gao, Xiaojun Pan, Jian Gao, Huanfeng Jiang, Gaoqing Yuan, and Yingwei Li
Organic Letters 2015 Volume 17(Issue 4) pp:1038-1041
Publication Date(Web):February 11, 2015
DOI:10.1021/acs.orglett.5b00170
A novel synthesis recipe for β-alkoxy methyl sulfides was developed via NH4I-mediated three-component oxysulfenylation reaction of styrenes with DMSO and alcohols. This method features simple operation and readily available starting materials, and it provides an alternative sulfenylating agent generated from DMSO for oxysulfenylation reactions.
Co-reporter:Xiaofang Gao, Xiaojun Pan, Jian Gao, Huawen Huang, Gaoqing Yuan and Yingwei Li
Chemical Communications 2015 vol. 51(Issue 1) pp:210-212
Publication Date(Web):04 Nov 2014
DOI:10.1039/C4CC07606K
A novel ammonium iodide-induced sulfonylation of alkenes with DMSO and water toward the synthesis of vinyl methyl sulfones is described. The process proceeded smoothly under metal-free conditions with high stereoselectivity and good functional group tolerance. The reaction mechanism was revealed to proceed through a domino reaction of oxidation and elimination after the radical addition to alkenes.
Co-reporter:Suntao Wu, Liyu Chen, Biaolin Yin and Yingwei Li
Chemical Communications 2015 vol. 51(Issue 48) pp:9884-9887
Publication Date(Web):15 May 2015
DOI:10.1039/C5CC02741A
We present a general strategy for incorporating π-conjugated NNN-chelators (e.g., terpyridyl moiety) into a porous metal–organic framework (MOF) MIL-101(Cr) by using the “click” post-functionalization. The functionalized MOF could be used as a platform for metalation to yield highly active and stable single-site heterogeneous metal (e.g., Ru(III)) catalysts.
Co-reporter:Xuan Qiu, Xi Wang and Yingwei Li
Chemical Communications 2015 vol. 51(Issue 18) pp:3874-3877
Publication Date(Web):29 Jan 2015
DOI:10.1039/C4CC09933H
A simple and versatile synthetic route is develped to modulate the growth and distribution of MOF–graphene oxide (GO) nanohybrid materials, achieving dense and ordered MOFs featuring different sizes and morphologies on GO. After pyrolysis, the resulting metal-containing/rGO nanomaterials demonstrate a superior catalytic activity in organic transformations.
Co-reporter:Jilan Long, Ying Zhou and Yingwei Li
Chemical Communications 2015 vol. 51(Issue 12) pp:2331-2334
Publication Date(Web):22 Dec 2014
DOI:10.1039/C4CC08946D
A novel non-noble Co@C–N catalytic system has been developed for catalytic transfer hydrogenation reactions. Co@C–N was found to be highly active and selective in the hydrogenation of a variety of unsaturated bonds with isopropanol in the absence of base additives.
Co-reporter:Xi Wang, Wei Zhong and Yingwei Li
Catalysis Science & Technology 2015 vol. 5(Issue 2) pp:1014-1020
Publication Date(Web):29 Oct 2014
DOI:10.1039/C4CY01147C
Nanoscale Co-based carbon materials were prepared by simple thermolysis of a Co-containing metal–organic framework (MOF), ZIF-67, at different temperatures and their catalytic performance for low-temperature CO oxidation was evaluated. Co/C-600, which was obtained from ZIF-67 pyrolysis at 600 °C, exhibited high catalytic activity for CO oxidation even at a temperature as low as −30 °C. The calculated apparent activation energy of CO oxidation over the Co/C-600 catalyst was around 22 kJ mol−1. Moreover, the CO conversion remained unchanged at 100% after 24 h time on stream at room temperature, demonstrating good long-term stability. The results obtained after the introduction of moisture (H2O content, ~500 ppm) into the feed gas showed that the Co/C catalyst was tolerant of wet conditions, showing an unusual temperature-dependent catalytic behavior. Intensive investigation of the catalytic performance led to the conclusion that adsorption of H2O molecules in the micropores of the catalyst caused this unusual catalytic behavior. This finding was supported by in situ FTIR spectroscopic experiments under both dry and wet conditions. Moreover, the catalytic activity of the Co/C material for CO oxidation could be fully recovered by mild heating treatment.
Co-reporter:Hongli Liu, Zhong Li, and Yingwei Li
Industrial & Engineering Chemistry Research 2015 Volume 54(Issue 5) pp:1487
Publication Date(Web):January 22, 2015
DOI:10.1021/ie504357r
A novel Pt-Lewis acid collaborative catalyst system for selective hydrogenation of cinnamaldehyde is developed. The Pt/MIL-101 catalyst is able to efficiently catalyze the selective hydrogenation of the C═C group in cinnamaldehyde to hydrocinnamaldehyde at atmospheric pressure and room temperature with >99.9% selectivity at conversions >99.9%. The remarkably enhanced catalytic activity and selectivity of Pt/MIL-101 can be attributed to the synergism effect between highly dispersed Pt and Lewis acid sites. In situ ATR-IR spectroscopic studies and reaction results demonstrated that the Lewis acid sites on MIL-101 suppressed the reactivity of the C═O bond in cinnamaldehyde while enhancing the hydrogenation activity of the conjugated C═C bond through a strong interaction with the C═O bond, which subsequently inhibited the consecutive hydrogenation of the produced hydrocinnamaldehyde. The kinetic parameters of cinnamaldehyde hydrogenation over the Pt/MIL-101 catalyst were investigated, and a kinetic model was established based on the reaction mechanism and compared with experimental observations.
Co-reporter:Liyu Chen, Sylvie Rangan, Jing Li, Huanfeng Jiang and Yingwei Li
Green Chemistry 2014 vol. 16(Issue 8) pp:3978-3985
Publication Date(Web):03 Jul 2014
DOI:10.1039/C4GC00314D
The organic palladium complex Pd(H2bpydc)Cl2 (H2bpydc = 2,2′-bipyridine-5,5′-dicarboxylic acid) was immobilized on a porous metal–organic framework UiO-67 (Zr6O4(OH)4(bpdc)6, bpdc = para-biphenyldicarboxylate) using a direct incorporation strategy. The use of a large amount of the H2bpdc ligand (90 mol% of the mixed ligands) that can't chelate the Pd complex allowed the formation of isolated Pd single active sites uniformly distributed in the MOF network. Pd(II) doped UiO-67 is isostructural to the parent UiO-67 framework, with a high surface area and pore volume of ca. 2000 m2 g−1 and 0.79 cm3 g−1, respectively. The material was highly efficient in the catalytic conversion of aryl chlorides, showing remarkably higher activity than the homogeneous Pd counterparts. High yields were achieved in Heck and Suzuki–Miyaura coupling reactions of chloroarenes bearing a wide range of substituents. Moreover, the catalyst was recoverable and reusable, giving essentially identical activity after at least 5 cycles. The combination of the advantages of both homogeneous molecular Pd catalysts and solid MOF structures in this system may bring new opportunity in the development of highly active heterogeneous palladium catalysts for a variety of Pd-catalyzed transformations.
Co-reporter:Liyu Chen, Huirong Chen, Rafael Luque and Yingwei Li
Chemical Science 2014 vol. 5(Issue 10) pp:3708-3714
Publication Date(Web):15 Jul 2014
DOI:10.1039/C4SC01847H
A novel synthesis strategy is developed to encapsulate palladium precursors through ligand design prior to MOF assembly, achieving uniformly distributed palladium NPs inside the cavities of MOFs. This strategy can avoid the different diffusion resistance between external and internal surfaces, and thus allow metal precursors to be easily deposited into the pores and evenly distributed within MOF networks. The embedded Pd NPs exhibited excellent shape-selectivity in olefin hydrogenation, as well as high catalytic efficiencies in aerobic oxidation of alcohols and reduction of nitrobenzene, showing significantly enhanced catalytic activity and stability as compared to those synthesized using a traditional impregnation method. The superior catalytic activity and stability came from the synergetic effects of nano-confinement and electron-donation offered by the MOF framework.
Co-reporter:Liyu Chen, Huirong Chen and Yingwei Li
Chemical Communications 2014 vol. 50(Issue 94) pp:14752-14755
Publication Date(Web):08 Oct 2014
DOI:10.1039/C4CC06568A
In this work, the first example of a facile one-pot route for the synthesis of Pd@MOF composites without additional stabilizing agents is developed. The as-synthesized MOF composite shows high activity and chemoselectivity in the hydrogenation of cinnamaldehyde even under atmosphere pressure of H2 and at room temperature.
Co-reporter:Cuihua Bai, Siping Jian, Xianfang Yao and Yingwei Li
Catalysis Science & Technology 2014 vol. 4(Issue 9) pp:3261-3267
Publication Date(Web):02 Jul 2014
DOI:10.1039/C4CY00488D
A novel, highly efficient, and phosphine-free heterogeneous palladium-MOF catalytic system for the carbonylative Sonogashira coupling of terminal alkynes with aryl iodides was developed. The catalyst could efficiently promote the carbonylative coupling reaction under atmospheric pressure of CO, affording the corresponding aryl α,β-alkynyl ketones in good to excellent yields. Besides high activity and selectivity, the proposed catalytic system features a broad substrate scope for both alkynes and aryl iodides. Moreover, the heterogeneous catalyst was recyclable, showed negligible metal leaching, and could be reused at least five times without significant loss in catalytic efficiency under the investigated conditions.
Co-reporter:Weiping Qin, Wenxiu Cao, Hongli Liu, Zhong Li and Yingwei Li
RSC Advances 2014 vol. 4(Issue 5) pp:2414-2420
Publication Date(Web):25 Nov 2013
DOI:10.1039/C3RA45983G
A series of Pd-doped MIL-101 samples with different Pd content and valence state have been prepared and employed as adsorbents for toluene adsorption and hydrogen storage for the first time. Compared with the parent MIL-101, PdCl2-functionalized MOF exhibited remarkably increased adsorption capacity for toluene under both low and high vapor concentrations. The toluene uptake of the 3 wt% PdCl2/MIL-101 at P/P0 = 0.06 was ca. 660 mg g−1 (i.e., 7.2 mmol g−1), representing an enhancement of 450% over that of unmodified MIL-101. Moreover, the adsorption of toluene on the PdCl2/MIL-101 sorbents was totally reversible. PdCl2/MIL-101 could be simply reduced by NaBH4 and hydrogen to prepare Pd nanoparticles immobilized on MIL-101. The hydrogen storage studies indicated that the reversible storage capacities on the Pd/MIL-101 samples at room temperature were enhanced by a factor of 1.5–2.3 compared with that of the parent MIL-101. It could be concluded that the size of the Pd nanoparticles and the Pd doping amount on the MIL-101 were crucial factors that determined the enhancement of the hydrogen storage capacity of the Pd/MIL-101 materials.
Co-reporter:Xuan Qiu; Christophe Len; Rafael Luque; Yingwei Li
ChemSusChem 2014 Volume 7( Issue 6) pp:1684-1688
Publication Date(Web):
DOI:10.1002/cssc.201301340
Abstract
A highly efficient, simple, and versatile transition-metal-free metal–organic framework catalytic system is proposed for the oxidative coupling of amines to imines. The catalytic protocol features high activities and selectivities to target products; compatibility with a variety of substrates, including aliphatic amines and secondary amines; and the possibility to efficiently and selectively promote amine cross-coupling reactions. A high stability and recyclability of the catalyst is also observed under the investigated conditions. Insights into the reaction mechanism indicate the formation of a superoxide species able to efficiently promote oxidative couplings.
Co-reporter:Jilan Long, Hongli Liu, Shijian Wu, Shijun Liao, and Yingwei Li
ACS Catalysis 2013 Volume 3(Issue 4) pp:647
Publication Date(Web):March 11, 2013
DOI:10.1021/cs300754k
Gold (Au) and palladium (Pd) nanoparticles dispersed on a zeolite-type metal–organic framework (i.e., MIL-101) were prepared via a simple colloidal method. The catalysts were characterized by powder X-ray diffraction, N2 physical adsorption, atomic absorption spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Au and Pd were mostly in the form of bimetallic alloys on the MIL-101 support. The Au–Pd/MIL-101 was active and selective in the oxidation of a variety of saturated (including primary, secondary, and tertiary) C–H bonds with molecular oxygen. For the liquid-phase oxidation of cyclohexane, cyclohexane conversion exceeding 40% was achieved (TOF: 19 000 h–1) with >80% selectivity to cyclohexanone and cyclohexanol under mild solvent-free conditions. Moreover, the Au–Pd alloy catalyst exhibited higher reactivity than their pure metal counterparts and an Au + Pd physical mixture. The high activity and selectivity of Au–Pd/MIL-101 in cyclohexane aerobic oxidation may be correlated to the synergistic alloying effect of bimetallic Au–Pd nanoparticles.Keywords: bimetallic catalysts; gold; metal−organic frameworks; oxidation; palladium; saturated C−H bonds
Co-reporter:Gongzhou Chen, Shijian Wu, Hongli Liu, Huanfeng Jiang and Yingwei Li
Green Chemistry 2013 vol. 15(Issue 1) pp:230-235
Publication Date(Web):22 Nov 2012
DOI:10.1039/C2GC36618E
Highly dispersed palladium nanoparticles were deposited on an acidic MOF (MIL-101) by using a simple colloidal method. The resulting Pd/MIL-101 catalyst was highly active in the liquid-phase aerobic oxidation of a wide range of alcohols including benzyl, allylic, aliphatic and heterocyclic alcohols as well as diols, affording the desired oxidation products in high yields under base-free and mild conditions. The catalyst was shown to be able to efficiently catalyze aerobic oxidation even at ambient temperature using air instead of pure O2. The solvent-free oxidation of benzyl alcohol gave a remarkably high turnover frequency (TOF) of approximately 16900 h−1. However, the catalytic activity was significantly suppressed when ethylenediamine was grafted on the uncoordinated Cr sites of the MIL-101 support, which suggests that the open Cr sites might play an important role in promoting the oxidation of alcohols in the present catalytic system.
Co-reporter:Yuzhi Li, Chao Huangfu, Haijun Du, Wenbin Liu, Yingwei Li, Jianshan Ye
Journal of Electroanalytical Chemistry 2013 Volume 709() pp:65-69
Publication Date(Web):15 November 2013
DOI:10.1016/j.jelechem.2013.09.017
•Metal-organic framework MIL-101 modified carbon paste electrode was fabricated.•The electrode enhances the electron transfer of [Fe(CN)6]3-/4- redox couple.•The electrode shows excellent electrocatalysis for the oxidation of DA and UA.•The novel electrode is attractive for electrochemical sensing application.Carbon paste electrode (CPE) modified with metal–organic framework MIL-101 (MIL-CPE) was developed. The morphological characteristics of MIL-101 were characterized by scanning electron microscope (SEM) and N2 physical adsorption experiments. Electrochemical sensing features were studied by electrochemical impedance spectroscopy and cyclic voltammetry. The charge transfer resistance of [Fe(CN)6]3−/4− couple at the MIL-CPE was about 400 Ω which was considerably small than that of CPE. An enhanced electrocatalytic activity towards oxidation of dopamine (DA) and uric acid (UA) were observed with oxidative potentials of 218 mV for DA and 336 mV for UA at the MIL-CPE, respectively. Thus, the MIL-101 has great potential for applications in electrochemical sensors.
Co-reporter:Yingyi Pan, Deyun Ma, Huimin Liu, Hao Wu, Dehua He and Yingwei Li
Journal of Materials Chemistry A 2012 vol. 22(Issue 21) pp:10834-10839
Publication Date(Web):23 Apr 2012
DOI:10.1039/C2JM30867C
A novel Tm-containing metal–organic framework, [Tm(μ2-L)(μ4-L)0.5(H2O)2]·3H2O (Tm-MOF), was prepared from the hydrothermal reaction of Tm(NO3)3 with 5-methylpyrazine-2-carboxylic acid in water. The 2,5-pyrazinedicarboxylate ligand (L) in Tm-MOF was formed in situ from 5-methylpyrazine-2-carboxylic acid under the above conditions. Tm-MOF is a three-dimensional (3D) coordination network with 1D open channels running across the coordination layers. Each L in bridging mode μ2 contains two uncoordinated carbonyl groups which point to the channels. By using the predesigned Tm-MOF as a host, we have successfully incorporated small palladium nanoparticles into the channels by a simple impregnation method. The Pd/Tm-MOF catalyst exhibited a high catalytic activity in the hydrogenation of styrene. Moreover, the catalyst could be reused at least three times without loss of any activity. In contrast, a low dispersion of metal and a low activity in styrene hydrogenation were observed over the Pd catalyst supported on ZIF-8, which has a similar surface area as the Tm-MOF, but no uncoordinated carbonyl groups. The results suggest that the uncoordinated carbonyl groups in the Tm-MOF may play an important role in facilitating the dispersion of Pd nanoparticles through an intermolecular interaction with the Pd cations in the course of immobilization.
Co-reporter:Hongli Liu, Yingwei Li, Huanfeng Jiang, Carolina Vargas and Rafael Luque
Chemical Communications 2012 vol. 48(Issue 67) pp:8431-8433
Publication Date(Web):16 Jul 2012
DOI:10.1039/C2CC32024J
An unprecedented synergistic effect, obtained for rationally designed Au–Pd alloy nanoparticles supported on an acidic metal–organic framework (MOF), in the aerobic oxidation of the primary C–H bonds in toluene and derivates is reported.
Co-reporter:Bizhen Yuan, Deyun Ma, Xi Wang, Zhong Li, Yingwei Li, Huimin Liu and Dehua He
Chemical Communications 2012 vol. 48(Issue 8) pp:1135-1137
Publication Date(Web):14 Dec 2011
DOI:10.1039/C2CC16923A
A new microporous amino-functionalized metal–organic framework has been synthesized by direct self-assembly, which exhibits high moisture-stability, acceptable capacity, and unprecedented high selectivity for CO2 over CH4, suggesting its potential application in gas separation processes like natural gas and biogas upgrading.
Co-reporter:Jilan Long, Liming Wang, Xingfa Gao, Cuihua Bai, Huanfeng Jiang and Yingwei Li
Chemical Communications 2012 vol. 48(Issue 99) pp:12109-12111
Publication Date(Web):08 Nov 2012
DOI:10.1039/C2CC36733E
A metal–organic framework with open 2,2′-bipyridine sites can efficiently activate molecular oxygen for selective oxidation of a variety of saturated hydrocarbons with unprecedented activities and selectivities.
Co-reporter:Hongli Liu, Biaolin Yin, Zhiqiang Gao, Yingwei Li and Huanfeng Jiang
Chemical Communications 2012 vol. 48(Issue 14) pp:2033-2035
Publication Date(Web):09 Jan 2012
DOI:10.1039/C2CC16790E
A novel heterogeneous catalysis system using metal–organic frameworks as catalyst demonstrated excellent chemo- and regioselectivity for the direct arylation of unactivated arenes with aryl iodides/bromides without the assistance of any transition metals.
Co-reporter:Yuting Huang, Weiping Qin, Zhong Li and Yingwei Li
Dalton Transactions 2012 vol. 41(Issue 31) pp:9283-9285
Publication Date(Web):05 Jul 2012
DOI:10.1039/C2DT30950E
A new dimethyl-functionalized UiO-66 framework exhibits higher physicochemical stability, larger CO2 uptake, and an enhanced heat of adsorption in comparison with what was previously observed for analogous UiO-66 type MOFs.
Co-reporter:Man Wang, Bizhen Yuan, Tongmei Ma, Huanfeng Jiang and Yingwei Li
RSC Advances 2012 vol. 2(Issue 13) pp:5528-5530
Publication Date(Web):24 May 2012
DOI:10.1039/C2RA20730C
A novel and efficient heterogeneous catalyst system based on CuI immobilized on a MOF material for the O-arylation of phenols and alcohols with aryl halides under ligand-free conditions is reported.
Co-reporter:Hongli Liu;Gongzhou Chen; Huanfeng Jiang; Yingwei Li; Rafael Luque
ChemSusChem 2012 Volume 5( Issue 10) pp:1892-1896
Publication Date(Web):
DOI:10.1002/cssc.201200611
Co-reporter:Deyun Ma, Yingwei Li and Zhong Li
Chemical Communications 2011 vol. 47(Issue 26) pp:7377-7379
Publication Date(Web):31 May 2011
DOI:10.1039/C1CC11752A
The introduction of hydrophobic groups (e.g.methyl) at the most adjacent sites of each and every coordinating nitrogen atom of the bipyridine pillar linker in a carboxylate-based bridging MOF could shield the metal ions from attack by water molecules, and thus enhance the water resistance of the MOF structure significantly.
Co-reporter:Hongli Liu;Rafael Luque;Huanfeng Jiang
Advanced Synthesis & Catalysis 2011 Volume 353( Issue 17) pp:3107-3113
Publication Date(Web):
DOI:10.1002/adsc.201100479
Abstract
A water-tolerant bifunctional heterogeneous catalyst is able to effectively catalyse the selective hydrogenation of phenol to cyclohexanone in water at atmospheric pressure and room temperature with >99.9% selectivity to cyclohexanone at phenol conversions >99.9%. The catalyst was found to be highly active and reusable, giving identical activities and selectivities after >5 uses. Moreover, this reported simple bifunctional catalyst is also able to hydrogenate a range of substituted phenols in high yields under the investigated aqueous conditions.
Co-reporter:Wenxiu Cao ; Yingwei Li ; Liming Wang ;Shijun Liao
The Journal of Physical Chemistry C 2011 Volume 115(Issue 28) pp:13829-13836
Publication Date(Web):June 28, 2011
DOI:10.1021/jp203607s
Hydrogen storage by spillover is a promising technique to enhance the hydrogen uptakes in metal–organic frameworks (MOFs) at room temperatures. However, to date, little is known on the structure–property relationships of MOFs for spillover storage. In this work, the effects of chemical composition of MOFs on hydrogen storage by spillover were studied systematically. Two series of MOFs with similar surface areas and formula units but different metal ions (M) or organic linkers (L), M(OH)BDC (BDC = terephthalate) or Zn4OL3, were prepared and employed as the receptors for spiltover hydrogen atoms. It was found that the M(OH)BDC series with various metal ions exhibited very close hydrogen capacities at room temperature. However, the functionalization of the BDC ligand in IRMOF-1 with various groups affected the storage capacity by spillover significantly. The decorations of functional groups with strong electrophilicity (i.e., electron-withdrawing ability) on the BDC linkers remarkably enhanced the hydrogen uptakes by spillover. The experimental results were in good agreement with the density functional theory (DFT) calculations, which showed that the hydrogenations of the ligands with electron-withdrawing groups were thermodynamically more favored than those with electron-donating ones on the MOF structures. The new findings could provide a potential way to fabricate new metal–organic frameworks with high hydrogen storage capacities by spillover at room temperature.
Co-reporter:Yingyi Pan, Bizhen Yuan, Yingwei Li and Dehua He
Chemical Communications 2010 vol. 46(Issue 13) pp:2280-2282
Publication Date(Web):13 Jan 2010
DOI:10.1039/B922061E
Palladium nanoparticles deposited on a chromium terephthalate MIL-101 is a highly efficient multifunctional catalyst for the one-step synthesis of methyl isobutyl ketone, with significantly higher activity than palladium on traditional materials, such as metal oxides and zeolites.
Co-reporter:Hongli Liu, Yaling Liu, Yingwei Li, Zhiyong Tang and Huanfeng Jiang
The Journal of Physical Chemistry C 2010 Volume 114(Issue 31) pp:13362-13369
Publication Date(Web):July 21, 2010
DOI:10.1021/jp105666f
The use of metal−organic frameworks (MOFs), an emerging class of porous materials, as supports for gold nanoparticles (NPs) may bring new opportunities in the development of highly active heterogeneous gold catalysts for a variety of catalytic reactions. Although currently a few examples of MOF-supported nanoparticulate Au have been reported, the preparation of an active Au NPs deposited MOF catalyst in solution is still a challenging research target. In this study, we report a highly efficient heterogeneous gold catalyst, which was deposited on a zeolite-type MOF (MIL-101) by a simple colloidal method with polyvinylpyrrolidone (PVP) as protecting agent using HAuCl4 as the Au precursor. The resulting Au/MIL-101 (CD/PVP) catalyst exhibited extremely high catalytic activities in liquid-phase aerobic oxidation of a wide range of alcohols, which could even efficiently catalyze the oxidation under ambient conditions in the absence of water or base. Moreover, the catalyst was easily recoverable and could be reused several times without leaching of metals or debasing of activity. The high dispersion of Au NPs and the electron donation effects of aryl rings to the Au NPs within the large cages of the MIL-101 support are suggested to be the main reasons for the observed high activities of the Au/MIL-101 (CD/PVP) catalyst in aerobic oxidation of alcohols under base-free conditions.
Co-reporter:Bizhen Yuan;Yingyi Pan, ;Biaolin Yin Dr. ;Huanfeng Jiang
Angewandte Chemie 2010 Volume 122( Issue 24) pp:4148-4152
Publication Date(Web):
DOI:10.1002/ange.201000576
Co-reporter:Bizhen Yuan;Yingyi Pan, ;Biaolin Yin Dr. ;Huanfeng Jiang
Angewandte Chemie International Edition 2010 Volume 49( Issue 24) pp:4054-4058
Publication Date(Web):
DOI:10.1002/anie.201000576
Co-reporter:De-Yun Ma, Hong-Li Liu, Ying-Wei Li
Inorganic Chemistry Communications 2009 Volume 12(Issue 9) pp:883-886
Publication Date(Web):September 2009
DOI:10.1016/j.inoche.2009.07.005
The self-assembly of isonicotinic acid with metal salts under hydrothermal conditions obtained two new 4d–4f coordination polymers, LnAg(OX)(IN)2·H2O (Ln = Nd (1); Eu (2), OX = oxalic acid, IN = isonicotinic acid). The 3D isostructural complexes 1 and 2 are constructed by the assembly of 2D layers, which are built by carboxylate groups of isonicotinic acid and oxalate ligands coordinating to metal centers, with 1D linear linkers completed by silver ions. Furthermore, the luminescent property of complex 2 was investigated.Two novel isostructural 3D 4d–4f coordination polymers, LnAg(OX)(IN)2·H2O (Ln = Nd (1); Eu (2), OX = oxalic acid, IN = isonicotinic acid), were prepared under hydrothermal condition and characterized by X-ray single-crystal diffraction, elemental analysis, FT-IR, TGA and photoluminescence measurements.
Co-reporter:Lina Chang, Yingwei Li
Molecular Catalysis (May 2017) Volume 433() pp:77-83
Publication Date(Web):1 May 2017
DOI:10.1016/j.mcat.2017.01.009
•Uniform Pt-Co bimetal alloy nanoparticles were firstly encapsulated within UiO-66 through a one-step method.•Cobalt ions were easily reduced under mild condition owing to the dissociation of H2 on the first reduced Pt.•PtCo@UiO-66 core–shell catalysts were highly active in the hydrogenation of nitrobenzene under atmospheric pressure of H2 and room temperature.•PtCo@UiO-66 showed good size selectivity in olefins hydrogenation under room temperature.•The embeded Pt-Co NPs exhibited excellent stability in the catalytic reaction due to the confinement effect offered by the MOF shell.Surfactant-free ultrafine and uniform Pt-Co alloy nanoparticles were encapsulated within UiO-66 with controllable size and spatial distribution by using a facile one-step strategy. The reduction of Co precursors (with a low reduction potential) under mild condition was achieved by the active Pt–H species that was produced from H2 dissociation on the first reduced Pt. The as-synthesized PtCo@UiO-66 core–shell catalysts exhibited superior synergy and catalytic activity in the hydrogenation of nitrobenzene under atmospheric pressure of H2 and room temperature. Most importantly, the confined catalysts were much more active, selective, and stable than the supported PtCo/UiO-66 material, owing to the confinement effect offered by the outer MOF shell.Surfactant-free ultrafine and uniform Pt-Co alloy nanoparticles are successfully encapsulated within UiO-66 with controllable size and spatial distribution by employing a facile one-step strategy. The as-synthesized PtCo@UiO-66core(*)–shell catalysts exhibit superior catalytic activity and stability in the hydrogenation of nitrobenzene under atmospheric pressure of H2 and room temperature.Download full-size image
Co-reporter:Weixia Wang, Yingwei Li, Rongjun Zhang, Dehua He, Hongli Liu, Shijun Liao
Catalysis Communications (15 May 2011) Volume 12(Issue 10) pp:875-879
Publication Date(Web):15 May 2011
DOI:10.1016/j.catcom.2011.02.001
Co3O4 nanoparticles were prepared from cobalt nitrate that was accommodated in the pores of a metal-organic framework (MOF) ZIF-8 (Zn(MeIM)2, MeIM = 2-methylimidazole) by using a simple liquid-phase method. The ZIF-8 host was removed by pyrolysis under air and subsequently washing with an NH4Cl–NH3·H2O aqueous solution. Transmission electron microscopy (TEM) analysis shows that the obtained Co3O4 is composed of separate nanoparticles with a mean size of 18 nm. The Co3O4 nanoparticles exhibit excellent catalytic activity, cycling stability, and long-term stability in the low temperature CO oxidation.Download full-size imageResearch Highlights► Pyrolysis of cobalt nitrate confined in the pore of a MOF yields nanoscale Co3O4. ► The MOF host is fully removed to yield neat Co3O4. ► The Co3O4 is composed of separate nanoparticles with a uniform size of ca. 18 nm. ► The Co3O4 exhibits excellent catalytic activity and stability in CO oxidation.
Co-reporter:Xi Wang, Wei Zhong and Yingwei Li
Catalysis Science & Technology (2011-Present) 2015 - vol. 5(Issue 2) pp:NaN1020-1020
Publication Date(Web):2014/10/29
DOI:10.1039/C4CY01147C
Nanoscale Co-based carbon materials were prepared by simple thermolysis of a Co-containing metal–organic framework (MOF), ZIF-67, at different temperatures and their catalytic performance for low-temperature CO oxidation was evaluated. Co/C-600, which was obtained from ZIF-67 pyrolysis at 600 °C, exhibited high catalytic activity for CO oxidation even at a temperature as low as −30 °C. The calculated apparent activation energy of CO oxidation over the Co/C-600 catalyst was around 22 kJ mol−1. Moreover, the CO conversion remained unchanged at 100% after 24 h time on stream at room temperature, demonstrating good long-term stability. The results obtained after the introduction of moisture (H2O content, ~500 ppm) into the feed gas showed that the Co/C catalyst was tolerant of wet conditions, showing an unusual temperature-dependent catalytic behavior. Intensive investigation of the catalytic performance led to the conclusion that adsorption of H2O molecules in the micropores of the catalyst caused this unusual catalytic behavior. This finding was supported by in situ FTIR spectroscopic experiments under both dry and wet conditions. Moreover, the catalytic activity of the Co/C material for CO oxidation could be fully recovered by mild heating treatment.
Co-reporter:Liyu Chen, Rafael Luque and Yingwei Li
Chemical Society Reviews 2017 - vol. 46(Issue 15) pp:NaN4630-4630
Publication Date(Web):2017/05/18
DOI:10.1039/C6CS00537C
The controllable encapsulation of nanoentities (such as metal nanoparticles, quantum dots, polyoxometalates, organic and metallorganic molecules, biomacromolecules, and metal–organic polyhedra) into metal–organic frameworks (MOFs) to form composite materials has attracted significant research interest in a variety of fields. These composite materials not only exhibit the properties of both the nanoentities and the MOFs but also display unique and synergistic functionalities. Tuning the sizes, compositions, and shapes of nanoentities encapsulated in MOFs enables the final composites to exhibit superior performance to those of the separate constituents for various applications. In this tutorial review article, we summarized the state-of-the-art development of MOFs containing encapsulated tunable nanoentities, with special emphasis on the preparation and synergistic properties of these composites.
Co-reporter:Deyun Ma, Yingwei Li and Zhong Li
Chemical Communications 2011 - vol. 47(Issue 26) pp:NaN7379-7379
Publication Date(Web):2011/05/31
DOI:10.1039/C1CC11752A
The introduction of hydrophobic groups (e.g.methyl) at the most adjacent sites of each and every coordinating nitrogen atom of the bipyridine pillar linker in a carboxylate-based bridging MOF could shield the metal ions from attack by water molecules, and thus enhance the water resistance of the MOF structure significantly.
Co-reporter:Jilan Long, Liming Wang, Xingfa Gao, Cuihua Bai, Huanfeng Jiang and Yingwei Li
Chemical Communications 2012 - vol. 48(Issue 99) pp:NaN12111-12111
Publication Date(Web):2012/11/08
DOI:10.1039/C2CC36733E
A metal–organic framework with open 2,2′-bipyridine sites can efficiently activate molecular oxygen for selective oxidation of a variety of saturated hydrocarbons with unprecedented activities and selectivities.
Co-reporter:Suntao Wu, Liyu Chen, Biaolin Yin and Yingwei Li
Chemical Communications 2015 - vol. 51(Issue 48) pp:NaN9887-9887
Publication Date(Web):2015/05/15
DOI:10.1039/C5CC02741A
We present a general strategy for incorporating π-conjugated NNN-chelators (e.g., terpyridyl moiety) into a porous metal–organic framework (MOF) MIL-101(Cr) by using the “click” post-functionalization. The functionalized MOF could be used as a platform for metalation to yield highly active and stable single-site heterogeneous metal (e.g., Ru(III)) catalysts.
Co-reporter:Yingyi Pan, Deyun Ma, Huimin Liu, Hao Wu, Dehua He and Yingwei Li
Journal of Materials Chemistry A 2012 - vol. 22(Issue 21) pp:NaN10839-10839
Publication Date(Web):2012/04/23
DOI:10.1039/C2JM30867C
A novel Tm-containing metal–organic framework, [Tm(μ2-L)(μ4-L)0.5(H2O)2]·3H2O (Tm-MOF), was prepared from the hydrothermal reaction of Tm(NO3)3 with 5-methylpyrazine-2-carboxylic acid in water. The 2,5-pyrazinedicarboxylate ligand (L) in Tm-MOF was formed in situ from 5-methylpyrazine-2-carboxylic acid under the above conditions. Tm-MOF is a three-dimensional (3D) coordination network with 1D open channels running across the coordination layers. Each L in bridging mode μ2 contains two uncoordinated carbonyl groups which point to the channels. By using the predesigned Tm-MOF as a host, we have successfully incorporated small palladium nanoparticles into the channels by a simple impregnation method. The Pd/Tm-MOF catalyst exhibited a high catalytic activity in the hydrogenation of styrene. Moreover, the catalyst could be reused at least three times without loss of any activity. In contrast, a low dispersion of metal and a low activity in styrene hydrogenation were observed over the Pd catalyst supported on ZIF-8, which has a similar surface area as the Tm-MOF, but no uncoordinated carbonyl groups. The results suggest that the uncoordinated carbonyl groups in the Tm-MOF may play an important role in facilitating the dispersion of Pd nanoparticles through an intermolecular interaction with the Pd cations in the course of immobilization.
Co-reporter:Yuting Huang, Weiping Qin, Zhong Li and Yingwei Li
Dalton Transactions 2012 - vol. 41(Issue 31) pp:NaN9285-9285
Publication Date(Web):2012/07/05
DOI:10.1039/C2DT30950E
A new dimethyl-functionalized UiO-66 framework exhibits higher physicochemical stability, larger CO2 uptake, and an enhanced heat of adsorption in comparison with what was previously observed for analogous UiO-66 type MOFs.
Co-reporter:Cuihua Bai, Siping Jian, Xianfang Yao and Yingwei Li
Catalysis Science & Technology (2011-Present) 2014 - vol. 4(Issue 9) pp:NaN3267-3267
Publication Date(Web):2014/07/02
DOI:10.1039/C4CY00488D
A novel, highly efficient, and phosphine-free heterogeneous palladium-MOF catalytic system for the carbonylative Sonogashira coupling of terminal alkynes with aryl iodides was developed. The catalyst could efficiently promote the carbonylative coupling reaction under atmospheric pressure of CO, affording the corresponding aryl α,β-alkynyl ketones in good to excellent yields. Besides high activity and selectivity, the proposed catalytic system features a broad substrate scope for both alkynes and aryl iodides. Moreover, the heterogeneous catalyst was recyclable, showed negligible metal leaching, and could be reused at least five times without significant loss in catalytic efficiency under the investigated conditions.
Co-reporter:Liyu Chen, Xiaodong Chen, Hongli Liu, Cuihua Bai and Yingwei Li
Journal of Materials Chemistry A 2015 - vol. 3(Issue 29) pp:NaN15264-15264
Publication Date(Web):2015/06/17
DOI:10.1039/C5TA02860D
The control over the size and location of metal nanoparticles (MNPs) within metal–organic frameworks (MOFs) is achieved in one step through a cooperative in situ metal precursor incorporation and on-site moderate reduction process, which is operated by a temperature control program. The choice of operation temperatures is based on the MOF assembly temperature (T1), and an elevated temperature (T2) to elicit the reducibility of DMF solvent to fabricate MNPs. Such a rational design could effectively introduce metal precursors into the pores of MOFs and on-site moderately reduce the embedded metal ions to generate tiny MNPs by the penetrated DMF, which could not be achieved by a quick heating process. The proposed methodology has been successfully applied to the one-step fabrication of ultrafine Pd NPs selectively encapsulated inside the pores of UiO-67 without any external reducing agents. The obtained Pd-in-UiO-67 shows superior catalytic activity and selectivity in the hydrogenation of styrene even at room temperature and atmospheric pressure of H2.
Co-reporter:Hongli Liu, Biaolin Yin, Zhiqiang Gao, Yingwei Li and Huanfeng Jiang
Chemical Communications 2012 - vol. 48(Issue 14) pp:NaN2035-2035
Publication Date(Web):2012/01/09
DOI:10.1039/C2CC16790E
A novel heterogeneous catalysis system using metal–organic frameworks as catalyst demonstrated excellent chemo- and regioselectivity for the direct arylation of unactivated arenes with aryl iodides/bromides without the assistance of any transition metals.
Co-reporter:Bizhen Yuan, Deyun Ma, Xi Wang, Zhong Li, Yingwei Li, Huimin Liu and Dehua He
Chemical Communications 2012 - vol. 48(Issue 8) pp:NaN1137-1137
Publication Date(Web):2011/12/14
DOI:10.1039/C2CC16923A
A new microporous amino-functionalized metal–organic framework has been synthesized by direct self-assembly, which exhibits high moisture-stability, acceptable capacity, and unprecedented high selectivity for CO2 over CH4, suggesting its potential application in gas separation processes like natural gas and biogas upgrading.
Co-reporter:Liyu Chen;Binbin Huang;Xuan Qiu;Xi Wang;Rafael Luque
Chemical Science (2010-Present) 2016 - vol. 7(Issue 1) pp:NaN233-233
Publication Date(Web):2015/12/17
DOI:10.1039/C5SC02925B
The possibility of using inner cavities within metal–organic frameworks (MOFs) as templates for the fabrication of tiny metal nanoparticles (NPs) was attempted in this work. An unprecedented design of Pd@Ag core–shell NPs on MOFs via a seed mediated growth strategy is reported and attributed to the presence of activated physisorbed hydrogen atoms on embedded Pd NPs as reducing agents to selectively direct the deposition of Ag onto Pd while minimizing the Ag self-nucleation. The obtained Pd@Ag core–shell NPs exhibited a significant increase in selectivity in the partial hydrogenation of phenylacetylene as compared to their monometallic counterparts, due to the surface dilution and electron modification of the surface Pd sites by Ag deposition. Pd@Ag NPs also possessed an unprecedented high stability and recyclability in the catalytic reactions, related to the nano-confinement effect and the strong metal–support interaction offered by the MOF framework.
Co-reporter:Xiaofang Gao, Xiaojun Pan, Jian Gao, Huawen Huang, Gaoqing Yuan and Yingwei Li
Chemical Communications 2015 - vol. 51(Issue 1) pp:NaN212-212
Publication Date(Web):2014/11/04
DOI:10.1039/C4CC07606K
A novel ammonium iodide-induced sulfonylation of alkenes with DMSO and water toward the synthesis of vinyl methyl sulfones is described. The process proceeded smoothly under metal-free conditions with high stereoselectivity and good functional group tolerance. The reaction mechanism was revealed to proceed through a domino reaction of oxidation and elimination after the radical addition to alkenes.
Co-reporter:Jilan Long, Ying Zhou and Yingwei Li
Chemical Communications 2015 - vol. 51(Issue 12) pp:NaN2334-2334
Publication Date(Web):2014/12/22
DOI:10.1039/C4CC08946D
A novel non-noble Co@C–N catalytic system has been developed for catalytic transfer hydrogenation reactions. Co@C–N was found to be highly active and selective in the hydrogenation of a variety of unsaturated bonds with isopropanol in the absence of base additives.
Co-reporter:Xuan Qiu, Xi Wang and Yingwei Li
Chemical Communications 2015 - vol. 51(Issue 18) pp:NaN3877-3877
Publication Date(Web):2015/01/29
DOI:10.1039/C4CC09933H
A simple and versatile synthetic route is develped to modulate the growth and distribution of MOF–graphene oxide (GO) nanohybrid materials, achieving dense and ordered MOFs featuring different sizes and morphologies on GO. After pyrolysis, the resulting metal-containing/rGO nanomaterials demonstrate a superior catalytic activity in organic transformations.
Co-reporter:Liyu Chen, Huirong Chen and Yingwei Li
Chemical Communications 2014 - vol. 50(Issue 94) pp:NaN14755-14755
Publication Date(Web):2014/10/08
DOI:10.1039/C4CC06568A
In this work, the first example of a facile one-pot route for the synthesis of Pd@MOF composites without additional stabilizing agents is developed. The as-synthesized MOF composite shows high activity and chemoselectivity in the hydrogenation of cinnamaldehyde even under atmosphere pressure of H2 and at room temperature.
Co-reporter:Hongli Liu, Lina Chang, Liyu Chen and Yingwei Li
Journal of Materials Chemistry A 2015 - vol. 3(Issue 15) pp:NaN8033-8033
Publication Date(Web):2015/03/11
DOI:10.1039/C5TA00030K
The encapsulation of metal nanoparticles (MNPs) into metal–organic frameworks has generated recent research because of the promising novel physical and chemical properties originating from synergetic interactions between MNPs and MOFs. However, the development of a facile one-step approach for the incorporation of tiny MNPs within MOFs without additional stabilizing agents and reductants remains a great challenge. Herein, we report a new and general synthesis strategy for MNPs@MOFs that allows preferential self-assembly of MOFs around the in situ formed MNP surface by directly mixing both the reactive metal (e.g., H2PtCl6) and MOF precursors in DMF. This in situ one-step assembly approach is applicable to various MOFs, affording well-defined Pt@MOF composites with highly dispersed naked Pt NPs in narrow diameter distribution. The resulting Pt@MOF nanocomposites exhibit excellent stability, significantly enhanced catalytic activity and selectivity as compared to the commercial Pt/C in liquid-phase aerobic oxidation of alcohols.
Co-reporter:Liyu Chen, Huirong Chen, Rafael Luque and Yingwei Li
Chemical Science (2010-Present) 2014 - vol. 5(Issue 10) pp:NaN3714-3714
Publication Date(Web):2014/07/15
DOI:10.1039/C4SC01847H
A novel synthesis strategy is developed to encapsulate palladium precursors through ligand design prior to MOF assembly, achieving uniformly distributed palladium NPs inside the cavities of MOFs. This strategy can avoid the different diffusion resistance between external and internal surfaces, and thus allow metal precursors to be easily deposited into the pores and evenly distributed within MOF networks. The embedded Pd NPs exhibited excellent shape-selectivity in olefin hydrogenation, as well as high catalytic efficiencies in aerobic oxidation of alcohols and reduction of nitrobenzene, showing significantly enhanced catalytic activity and stability as compared to those synthesized using a traditional impregnation method. The superior catalytic activity and stability came from the synergetic effects of nano-confinement and electron-donation offered by the MOF framework.
Co-reporter:Liyu Chen, Lei Zhang, Zhijie Chen, Hongli Liu, Rafael Luque and Yingwei Li
Chemical Science (2010-Present) 2016 - vol. 7(Issue 9) pp:
Publication Date(Web):
DOI:10.1039/C6SC01659F
Co-reporter:Yingyi Pan, Bizhen Yuan, Yingwei Li and Dehua He
Chemical Communications 2010 - vol. 46(Issue 13) pp:NaN2282-2282
Publication Date(Web):2010/01/13
DOI:10.1039/B922061E
Palladium nanoparticles deposited on a chromium terephthalate MIL-101 is a highly efficient multifunctional catalyst for the one-step synthesis of methyl isobutyl ketone, with significantly higher activity than palladium on traditional materials, such as metal oxides and zeolites.
Co-reporter:Hongli Liu, Yingwei Li, Huanfeng Jiang, Carolina Vargas and Rafael Luque
Chemical Communications 2012 - vol. 48(Issue 67) pp:NaN8433-8433
Publication Date(Web):2012/07/16
DOI:10.1039/C2CC32024J
An unprecedented synergistic effect, obtained for rationally designed Au–Pd alloy nanoparticles supported on an acidic metal–organic framework (MOF), in the aerobic oxidation of the primary C–H bonds in toluene and derivates is reported.
Co-reporter:Huirong Chen, Kui Shen, Junying Chen, Xiaodong Chen and Yingwei Li
Journal of Materials Chemistry A 2017 - vol. 5(Issue 20) pp:NaN9945-9945
Publication Date(Web):2017/04/19
DOI:10.1039/C7TA02184D
Semiconducting metal oxides have been considered as effective photocatalysts for the degradation of organic pollutants to decolorize contaminated water. However, the poor performance and difficulty in recycling greatly hinder their practical application. Herein, we designed and fabricated, for the first time, a novel ZnO@C–N–Co core–shell nanocomposite towards efficient and recyclable photocatalysis by directly pyrolyzing a hollow Zn/Co–ZIF matrix consisting of a ZIF-8 shell with some Co–ZIF nanoplates inside the hollow cavity. It was demonstrated that the ZIF-8-shell-derived ZnO nanoparticles could spontaneously agglomerate and move to the hollow cavity while the internal Co NPs transferred inversely to the ligand-derived N–C shell at suitable pyrolysis temperature, resulting in the unique ZnO@C–N–Co core–shell structure. This unique nanostructure possessed the following superior properties: (1) a core–shell structure may make the intermediate ZnO much more stable during the reaction; (2) a porous carbon shell can not only provide a high BET specific area and thus high adsorption capability for reactants, but can also inhibit the recombination of photogenerated electrons and holes; (3) the embedded Co NPs were able to provide richer electron traps that further suppress the recombination of electrons and holes. As exemplified for the degradation of methyl orange, the ZnO@C–N–Co showed a significantly improved performance and excellent recyclability due to the highly synergistic effects between the C–N–Co shell and the robust ZnO. This strategy for the synthesis of MOF-derived core–shell nanomaterials could offer prospects for developing highly efficient photocatalysts.
Co-reporter:Liyu Chen, Weihao Huang, Xiujun Wang, Zhijie Chen, Xianfeng Yang, Rafael Luque and Yingwei Li
Chemical Communications 2017 - vol. 53(Issue 6) pp:NaN1187-1187
Publication Date(Web):2016/12/23
DOI:10.1039/C6CC09270E
A series of crown-jewel Pd-based bimetallic nanostructures with tunable composition are fabricated inside the pores of an MOF via a hydride-induced-reduction strategy, exhibiting high activity and stability in the hydrogenation of nitrobenzene.
Co-reporter:Xi Wang and Yingwei Li
Journal of Materials Chemistry A 2016 - vol. 4(Issue 14) pp:NaN5257-5257
Publication Date(Web):2016/03/09
DOI:10.1039/C6TA00324A
Metal-free nanocarbon catalysts have attracted much attention in recent years for their advantages of corrosion resistance, no heavy metal pollution and environmental friendliness as compared to metal-based catalysts. However, a facile preparation of heteroatom doped mesoporous carbon with a high catalytic efficiency is challenging. Here we report the development of a new kind of metal-free catalyst comprised of highly graphitized N-doped nanoporous carbons from direct carbonization of metal–organic frameworks. After metal etching, large specific surface areas and pore volumes, as well as high contents of sp2-bonded carbons are realized in the obtained carbons at the same time. As metal-free catalysts, these nitrogen-doped carbon materials exhibit excellent catalytic performances and robust stability in a series of oxidation reactions including aerobic oxidation of cyclohexane and toluene as well as oxidative coupling of amines. Systematic characterizations suggest that the accessible mesopores generated by chemical etching, and the homogeneous distribution of doped graphitic-type nitrogen should be responsible for the unprecedented performance of these carbon catalysts.
Co-reporter:Jilan Long, Kui Shen, Liang Chen and Yingwei Li
Journal of Materials Chemistry A 2016 - vol. 4(Issue 26) pp:NaN10262-10262
Publication Date(Web):2016/06/02
DOI:10.1039/C6TA00157B
Transition metal NPs and their alloy NPs have attracted significant attention due to their low cost and potential to replace noble-metal-based catalysts in many reaction systems; however, major challenges are still encountered when exploring cost-effective and scaleable strategies to prepare and attach them with optimal supports for maximizing their catalytic efficiency. Here, we report a facile and repeatable route to synthesize transition metal based nano-catalysts by first developing a series of new and novel N-donor multimetallic M–M′-MOFs [(M–M′(1,4-bdc)2(dabco)]·4DMF·1/2H2O, M/M′ = Co, Ni, Cu) by a facile mixed-metal approach and then directly pyrolyzing these hetero-nuclear MOFs under inert gas. In the pyrolysis process, the transition metal ions (two of Co, Ni, and Co) of M–M′-MOFs could be transformed into transition alloy nanoparticles while the surrounding N-containing ligands were polymerized to N-doped graphitic carbon, resulting in highly dispersed M/M′ alloy NPs embedded in the N-doped carbon matrix. The detailed characterization results revealed that the metal elements including Co, Ni, and Cu were uniformly distributed in every individual alloy NP and there existed an obvious synergetic activation of different transition metals and strong coordination interactions between metals of alloy NPs and N atoms. When being used in the transfer hydrogenation of nitriles in the absence of basic additives, the optimal Co–Ni(3:1)@C–N showed the best catalytic performance with 100% conversion of benzonitrile and over 98% yield for the desired product, which was almost 5 times more active than its monometallic counterparts. We believe that this MOF-templating strategy provides a facile and controllable route for the preparation of nanocatalysts based on transition metal NPs with high transfer hydrogenation performance.
![Anthracene, 9-[(1E)-2-(methylsulfonyl)ethenyl]-](http://img.cochemist.com/ccimg/918400/918341-17-0.png)
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