Co-reporter:Yueling Cao, Minghui Tang, Mingming Li, Jiang Deng, Fan Xu, Lei Xie, and Yong Wang
ACS Sustainable Chemistry & Engineering November 6, 2017 Volume 5(Issue 11) pp:9894-9894
Publication Date(Web):October 9, 2017
DOI:10.1021/acssuschemeng.7b01853
A novel N-doped carbon supported Rh catalyst was developed via one-pot pyrolysis of chitin and (NH4)3RhCl6. The catalyst exhibited excellent catalytic activity and recyclability for the hydrogenation of benzoic acid to cyclohexane carboxylic acid. Characterization indicated that the high catalytic performance of Rh/N–C-700 is mainly attributed to the proportion of Rh0 to Rh3+ and Rh particle size. More importantly, this novel synthesis strategy significantly increased the interaction between Rh nanoparticles and N-doped carbon in contrast with the conventional impregnation and NaBH4 reduction methods, thus preventing the Rh nanoparticles from migration, aggregation, and leaching from the support surface and therefore improving the reusability of the catalyst. This synthetic method may pave a new way for producing N-doped carbon supported metal catalysts from chitin on a large scale, which is attractive for industrial applications.Keywords: Benzoic acid; Chemoselective hydrogenation; Heterogeneous catalyst; N-Doped carbon; One-pot pyrolysis;
Co-reporter:Chunhong Chen, Haiyan Wang, Chuanlong Han, Jiang Deng, Jing Wang, Mingming Li, Minghui Tang, Haiyan Jin, and Yong Wang
Journal of the American Chemical Society February 22, 2017 Volume 139(Issue 7) pp:2657-2657
Publication Date(Web):February 1, 2017
DOI:10.1021/jacs.6b10841
The soft template method is broadly applied to the fabrication of hollow-structured nanomaterials. However, due to the instability and the typical spherical shape of these soft templates, the resultant particles have a spherical morphology with a wide size distribution. Herein, we developed a sustainable route to fabricate asymmetric flasklike hollow carbonaceous structures with a highly uniform morphology and a narrow size distribution using the soft template method. A dynamic growth mechanism induced by the synergetic interactions between template and biomass is proposed. The precursors (ribose) provide an acidic environment for sodium oleate during the hydrothermal process in which oleic acid nanoemulsions are initially formed and serve as both template and benign solvent for the amphiphilic derivatives of the precursor. Simultaneously, the cosurfactant P123 facilitates the uniform dispersion of the nanoemulsion and is believed to cause the carbonaceous shells to rupture, providing openings through which the intermediates can enter. These subtle interactions facilitate the formation of the flasklike, asymmetric, hollow, carbonaceous nanoparticles. Furthermore, this unique structure contributes to the high surface area (2335 m2 g–1) of the flasklike carbon particles, which enhances the performance of supercapacitors. These findings may open up an exciting field for exploring anisotropic carbonaceous nanomaterials and for understanding the related mechanisms to provide guidance for the design of increasingly complex carbonaceous materials.
Co-reporter:Yueling Cao, Shanjun Mao, Mingming Li, Yiqing Chen, and Yong Wang
ACS Catalysis December 1, 2017 Volume 7(Issue 12) pp:8090-8090
Publication Date(Web):October 11, 2017
DOI:10.1021/acscatal.7b02335
Developing novel and efficient catalysts is always an important theme for heterogeneous catalysis from fundamental and applied research points of view. In the past, carbon materials were used as supports for numerous heterogeneous catalysts because of their fascinating properties including high surface areas, tunable porosity, and functionality. Recently, the newly emerging N-doped carbon-supported metal catalysts have arguably experienced great progress and brought the most attention over the last decades in view of the fact that nitrogen doping can tailor the properties of carbon for various applications of interest. Compared with pristine carbon-supported metal catalysts, these catalysts normally show superior catalytic performance in many heterogeneous catalytic reactions because of the introduced various metal–support interactions from N doping. In this Perspective, we focus on the fabrication methods for N-doped carbon-supported metal catalysts and the catalytic application of these fascinating catalysts in several industrially relevant reactions, including hydrogenation, dehydrogenation, oxidation, and coupling. Notably, we try to elucidate the structure–activity correlations obtained from theoretical calculation, extensive characterization, and observed catalytic performances, thereby providing guidance for the rational design of advanced catalysts for heterogeneous catalysis.Keywords: coupling; dehydrogenation; heterogeneous catalysis; hydrogenation; metal/N-doped carbon; N-doped carbon; oxidation;
Co-reporter:Xiaobing Bao;Jing Wang;Xu Lian;Haiyan Jin;Shiping Wang
Journal of Materials Chemistry A 2017 vol. 5(Issue 31) pp:16249-16254
Publication Date(Web):2017/08/08
DOI:10.1039/C7TA01240C
Markedly minimizing the platinum (Pt) loading and increasing its mass activity are significant to drive down the cost of H2 production from water splitting. Herein, a novel electrocatalyst, Pt nanoparticles (NPs) anchored on Ni/nitrogen-doped graphene nanotubes (Pt/Ni@NGNTs), was designed and its exceptional catalytic performance towards hydrogen evolution reaction was demonstrated. Ni@NGNTs itself showed poor catalytic activity. Unexpectedly, when employed as a support, it increased the mass activity of the Pt metal by 30.1 times in an acidic electrolyte and 15.3 times in an alkaline electrolyte relative to that of commercial 20 wt% Pt/C. Moreover, the durability of Pt/Ni@NGNTs reached up to 50 h. Impressively, Pt NPs preferentially distributed around the protective graphene shells of the enclosed metal Ni, due to the enriched electron density and structural defects induced by Ni and N dopants. The electronic interactions between Pt and Ni@NGNTs tuned the electronic properties and greatly boosted catalytic performances of the anchored Pt NPs. The present catalyst shows significant potential for the synthesis of low cost, high performance Pt-based catalysts.
Co-reporter:Haiyan Wang, Chunmei Xu, Yiqing Chen, Yong Wang
Energy Storage Materials 2017 Volume 8(Volume 8) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.ensm.2017.05.007
Flexible solid-state supercapacitors (SCs) have shown great potential in portable electronics. However, the development of MnO2-based electrodes for flexible SCs is hampered by the low energy density, especially on the whole electrode basis, as a result of the small mass loading and poor utilization of MnO2. Here high mass loading of 4.5 mg/cm2 and large capacitance of 464 F/g (2088 mF/cm2) for MnO2 nanograsses were achieved by taking use of porous carbon cloth (TCC) which has large specific surface area. Benefiting from the full utilization of MnO2, high energy density of 841 μWh/cm2 and robust cyclic stability (96% capacitance retention after 20000 cycles) are achieved by assembling an efficient asymmetric supercapacitor (ASC) with 2 V operating voltage. These results open up new paths for developing high-performance electrode materials and applying for advanced energy storage devices.Download high-res image (242KB)Download full-size image
Co-reporter:Xiaobing Bao;Yutong Gong;Jiang Deng;Shiping Wang
Nano Research 2017 Volume 10( Issue 4) pp:1258-1267
Publication Date(Web):2017 April
DOI:10.1007/s12274-016-1374-5
The scalable preparation of multi-functional three-dimensional (3D) carbon nanotubes and graphene (CNTs-G) hybrids via a well-controlled route is urgently required and challenging. Herein, an easily operated, oxalic acid-assisted method was developed for the in situ fabrication of a 3D lasagna-like Fe-N-doped CNTs-G framework (LMFC) from a precursor designed at the molecular level. The well-organized architecture of LMFC was constructed by multi-dimensionally interconnected graphene and CNTs which derived from porous graphene sheets, to form a fundamentally robust and hierarchical porous structure, as well as favorable conductive networks. The impressive oxygen reduction reaction (ORR) performances in both alkaline and acidic conditions helped confirm the significance of this technically favorable morphological structure. This product was also the subject of research for the exploration of decisive effects on the performance of ORR catalysts with reasonable control variables. The present work further advances the construction of novel 3D carbon architectures via practical and economic routes.
Co-reporter:Jing Wang;Zhongzhe Wei;Haiyan Wang;Yiqing Chen
Journal of Materials Chemistry A 2017 vol. 5(Issue 21) pp:10510-10516
Publication Date(Web):2017/05/30
DOI:10.1039/C7TA02115A
Water splitting is the mainstay of contemporary energy conversion and storage engineering. The design of earth-abundant electrode materials without extra binders for an efficient hydrogen evolution reaction (HER) is critical in realizing the hydrogen economy in the push for future sustainable development. Herein, three-dimensional (3D) porous electrodes (denoted CoOx–CNT–CC) featuring CoOx nanoparticles (NPs) and carbon nanotubes (CNT) growing on activated carbon fiber were synthesized through a one-pot pyrolysis process. The achieved 3D electrodes acted as efficient electrocatalysts as well as current collectors for hydrogen production, greatly simplifying the electrode preparation process. Impressively, the electrodes exhibited high current density under low overpotential. The current density can reach up to ∼720 mA cm−2, an overpotential of ∼99 mV is required to reach a current density of 20 mA cm−2, and they function with a durability of up to 70 h. Beyond that, the electrodes still show superb catalytic properties at low temperature (the current density is 326 mA cm−2 even at 278 K) and in a neutral medium (the current density is 450 mA cm−2 in 1 M PBS).
Co-reporter:Lingfeng Shen, Shanjun Mao, Jianqing Li, Mingming Li, Ping Chen, Haoran Li, Zhirong Chen, Yong Wang
Journal of Catalysis 2017 Volume 350(Volume 350) pp:
Publication Date(Web):1 June 2017
DOI:10.1016/j.jcat.2017.01.021
•PdZn/CN@ZnO exhibits both high activity and high selectivity in the hydrogenation of MBY.•The substitution effect of corner and edge Pd atoms leads to selectivity improvement.•The introduction of nitrogen-doped carbon (CN) helps to improve the activity.•PdZn/CN@ZnO shows excellent stability in recycling experiments.•PdZn/CN@ZnO performs well in hydrogenation of other industrially relevant alkenols.This work highlights a novel hybrid catalyst, intermetallic PdZn on CN@ZnO (PdZn/CN@ZnO), which serves as a highly efficient heterogeneous catalyst for semihydrogenation of 2-methyl-3-butyn-2-ol utilizing water as the solvent. Compared with intermetallic PdZn on ZnO (PdZn/ZnO), PdZn/CN@ZnO displays almost sixfold higher TOF while retaining high selectivity. It is assumed that the introduction of biomass-derived hydrophilic nitrogen-doped carbon into the ZnO helped to promote catalyst dispersion in aqueous media, ensuring better mass transfer. Further experiments and theoretical calculations showed that from Pd particles to intermetallic PdZn, the decrease of corner and edge Pd atoms might be a factor leading to the improvement of selectivity. Recycling experiments demonstrated that the PdZn/CN@ZnO catalyst could be reused at least eight times without significant decrease in activity or selectivity. Furthermore, when applied to industrially relevant alkenols that are building molecules for the production of vitamin E, the present catalyst still offered excellent performance. It is expected that the present catalytic system will demonstrate its high potential for practical production of vitamin E.Download high-res image (76KB)Download full-size image
Co-reporter:Haiyan Jin;Shanjun Mao;Guopeng Zhan;Fan Xu;Xiaobing Bao
Journal of Materials Chemistry A 2017 vol. 5(Issue 3) pp:1078-1084
Publication Date(Web):2017/01/17
DOI:10.1039/C6TA09959A
Cost-effective and highly active electrocatalysts for the oxygen evolution reaction (OER) are critical to energy conversion and storage processes. Herein, a superior OER catalyst of Fe substituted α-Co(OH)2 (α-Co1−mFem(OH)2) has been synthesized by taking advantage of the large layered structure and good conductivity of α-Co(OH)2, in conjunction with the rich redox properties and abundance of Fe. The atomically layered α-Co4Fe(OH)x (Co/Fe = 4) nanoplates could effectively catalyze water oxidation at the onset potential of 0.26 V and its turnover frequency (TOF) was 11 and 5 times higher than those of α-Co(OH)2 and IrO2, respectively. The increased activity could be attributed to strong electronic interactions between Co and Fe. Density functional theory (DFT) calculations also demonstrated that the theoretical overpotential of α-Co1−mFem(OH)2 is obviously lower than that of α-Co(OH)2 and thus Fe doped α-Co(OH)2 displays a better activity. Moreover, the correlation between the Fe content and activity could be plotted as a volcano curve.
Co-reporter:Minghui Tang;Shanjun Mao;Xuefeng Li;Chunhong Chen;Mingming Li
Green Chemistry (1999-Present) 2017 vol. 19(Issue 7) pp:1766-1774
Publication Date(Web):2017/04/03
DOI:10.1039/C7GC00387K
On the way to exploring superior hydrogenation catalysts, Ir-based catalysts with a record catalytic activity (up to 40 h−1) for the hydrogenation of benzoic acid to cyclohexanecarboxylic acid under mild reaction conditions (85 °C, 0.1 MPa H2, in water) have been successfully developed. By excluding various factors, the experimental results showed that the main factor governing the activity discrepancy between the Ir-based catalysts is actually the dispersion stability of the supports (such as N-doped carbon, active carbon, SBA-15 and various metal oxides) in the reaction solution, rather than the interaction between the Ir active component and the supports. Combined with theoretical investigation from first principles, an activity volcano curve considering the competing adsorption between the reactants (H2) and solvent (H2O) for aqueous aromatic ring hydrogenation was presented for the first time. The high activity of Ir can be deduced by the proper discrepancy of dissociation energies or adsorption energies between H2 and H2O on the catalysts. This activity volcano curve provides guidance for further rational design of promising catalysts for benzoic acid or even aromatic ring hydrogenation under true reaction conditions for practical applications.
Co-reporter:Jing Wang, Shanjun Mao, Zeyan LiuZhongzhe Wei, Haiyan Wang, Yiqing Chen, Yong Wang
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 8) pp:
Publication Date(Web):February 6, 2017
DOI:10.1021/acsami.6b15377
The research of a robust catalytic system based on single NiOx electrocatalyst for hydrogen evolution reaction (HER) remains a huge challenge. Particularly, the factors that dominate the catalytic properties of NiOx-based hybrids for HER have not been clearly demonstrated. Herein, a convenient protocol for the fabrication of NiOx@bamboo-like carbon nanotube hybrids (NiOx@BCNTs) is designed. The hybrids exhibit superb catalytic ability and considerable durability in alkaline solution. A benchmark HER current density of 10 mA cm–2 has been achieved at an overpotential of ∼79 mV. In combination with the experimental results and density functional theory (DFT) calculations, this for the first time definitely validates that the inherent high Ni0 ratio and the Ni0 on the interface of Ni/NiO play a vital role in the outstanding catalytic performance. Especially, the Ni0 on the interface of Ni/NiO performs superior activity for water splitting compared with that of bulk Ni0. These conclusions provide guidance for the rational design of the future non-noble metallic catalysts.Keywords: DFT; electrocatalysis; hydrogen evolution reaction; interface; NiOx-based hybrids;
Co-reporter:Zhongzhe Wei, Yiqing Chen, Jing Wang, Diefeng Su, Minghui Tang, Shanjun Mao, and Yong Wang
ACS Catalysis 2016 Volume 6(Issue 9) pp:5816
Publication Date(Web):July 26, 2016
DOI:10.1021/acscatal.6b01240
Porous nitrogen-doped graphene layers encapsulating cobalt nanoparticles (NPs) were prepared by the direct pyrolysis process. The resulting hybrids catalyze the hydrogenation of diverse quinoline compounds to access the corresponding tetrahydro derivatives (THQs), important molecules present in fine and bulk chemicals. Near-quantitative yields of the corresponding THQs were obtained under optimized conditions. Notably, various useful substituted quinolines and other biologically important N-heteroarenes are also viable. The enhanced stability of the catalyst is ascribed to the encapsulation structure, which can enormously reduce the extent of leaching of base metals and protect metal NPs from growing larger. The achieved success in the encapsulation of metal NPs within graphene layers opens an avenue for the design of highly active and reusable heterogeneous catalysts for more challenging molecules.Keywords: chemoselective hydrogenation; encapsulated structure; metallic cobalt; N-doped graphene layers; quinoline
Co-reporter:Fan Xu, Yiqing Chen, Minghui Tang, Haiyan Wang, Jiang Deng, and Yong Wang
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 8) pp:4473
Publication Date(Web):July 11, 2016
DOI:10.1021/acssuschemeng.6b01196
Hydrothermal carbonization of biomass is an economic and sustainable technique for the fabrication of functional carbonaceous materials. However, the introduction of biomass into synthesis of ordered mesoporous carbon materials achieves slow progress due to complicated requirements. It is still challenging to prepare biomass-derived ordered mesoporous carbon materials. Herein, we report a simple and effective strategy to synthesize ordered mesoporous carbon materials from renewable and environment-friendly pentose using one-pot hydrothermal synthesis. The as-synthesized ordered mesoporous carbon materials show mesopores of two-dimensional hexagonal symmetry and rich functional groups. Mechanism studies indicate that the acid facilitates the self-assembly of carbon precursors and soft templates and therefore induced the formation of ordered mesoporous carbonaceous materials under hydrothermal conditions. This is the first report on the S0H+X–I+ self-assembly mechanism that achieves success in biomass system. In addition, the unique materials show outstanding performance as supports in catalytic hydrogenation. Significantly, this acid induced self-assembly strategy will open up new avenues for designing functional biomass-derived carbon materials.Keywords: Acid induced self-assembly; Biomass; Ordered mesoporous carbons
Co-reporter:Jiang Deng, Tianyi Xiong, Haiyan Wang, Anmin Zheng, and Yong Wang
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 7) pp:3750
Publication Date(Web):May 24, 2016
DOI:10.1021/acssuschemeng.6b00388
Porous carbon materials stemming from biomass have drawn increasing interest because of their sustainable properties. Cellulose, hemicellulose, and lignin are the three basic components of crude biomass, and were investigated to reveal their influence on the derived carbonaceous materials. Huge amounts of oxygen-containing functional groups in cellulose and hemicellulose tend to be eliminated as H2O, CO2, and CO and give micropores during pyrolysis, whereas lignin contains plentiful aromatic units which are chemically inert, and thus produce nonporous carbon materials. When the KHCO3 was introduced during the pyrolysis process, the plentiful hydroxyl in cellulose and hemicellulose underwent dehydration condensation among different parent polymers, which are responsible for the formation of macroporous structure. By contrast, The β-O-4 bands in lignin experience homolysis and give rise to benzene-containing units, which finally result in carbon nanosheets. Furthermore, we demonstrated the mixture of cellulose, hemicellulose, and lignin can display a three-dimensional porous structure (containing macropores, mesopores, and micropores) when less than 50% of lignin is contained.Keywords: Cellulose; Hemicellulose; Lignin; Porous carbon; Supercapacitor
Co-reporter:Diefeng Su, Zhongzhe Wei, Shanjun Mao, Jing Wang, Yi Li, Haoran Li, Zhirong Chen and Yong Wang
Catalysis Science & Technology 2016 vol. 6(Issue 12) pp:4503-4510
Publication Date(Web):02 Feb 2016
DOI:10.1039/C5CY02171E
Efficient and inexpensive catalysts are urgently desired for the hydrogenation of 2,3,5-trimethylbenzoquinone (TMBQ) to 2,3,5-trimethylhydroquinone (TMHQ), a key vitamin-E intermediate. In this study, a one-step method was developed to synthesize uniform cobalt-based NPs supported on porous nitrogen-doped carbon for the hydrogenation of TMBQ to TMHQ. The as-prepared catalyst shows a high yield (>90%) and selectivity (>99%) for TMBQ hydrogenation as well as α,β-unsaturated carbonyls. The satisfactory performance is attributed to the small particle size and homogeneous distribution. Meanwhile, metallic Co is proved to be responsible for the catalytic activity. Furthermore, density functional theory calculation discloses that the excellent chemoselectivity towards TMBQ is due to the preference for a desorption process over sequential hydrogenation of TMHQ. This novel material has great potential as a non-precious-metal catalyst for heterogeneous hydrogenation processes, due to its outstanding catalytic performance, simple preparation method and low production cost.
Co-reporter:Mingming Li, Fan Xu, Haoran Li and Yong Wang
Catalysis Science & Technology 2016 vol. 6(Issue 11) pp:3670-3693
Publication Date(Web):01 Apr 2016
DOI:10.1039/C6CY00544F
Developing novel and efficient catalysts is a critical step in common heterogeneous hydrogenation and oxidation reactions. Despite the frequent study of metal oxide-supported catalysts, porous carbon materials have also emerged as valuable potential catalysts. However, due to their highly microporous structures and inferior structural functionalities, traditional activated carbons (ACs) have become increasingly less popular for industrial applications. To deal with the disadvantages of ACs, tremendous efforts have been made to develop novel nitrogen-doped porous carbon (NPC) materials with novel features such as highly porous structures and abundant structural nitrogen heteroatom decoration. As catalysts or catalysts supports, NPC materials have shown superior activities in many applications covering a wide range of heterogeneous hydrogenation and oxidation reactions. In this contribution, we review the fabrication methods for NPC materials used in heterogeneous hydrogenations and oxidations and highlight the intrinsic catalytic mechanisms along with the catalyst design strategies.
Co-reporter:Haiyan Wang;Jiang Deng;Yiqing Chen;Fan Xu;Zhongzhe Wei
Nano Research 2016 Volume 9( Issue 9) pp:2672-2680
Publication Date(Web):2016 September
DOI:10.1007/s12274-016-1154-2
Hydrothermal carbonization (HTC) of biomass to produce one-dimensional carbon materials with hierarchical pores is of significant importance. Here, we fabricate composites of MnOx-encapsulated multiporous carbon nanofibers (M-MCNFs) from naturally available carbohydrates through a dopamine-assisted HTC/ templating process. The introduction of dopamine aids in the formation of the morphology of carbon nanofibers (CNFs) by enhancing the interactions between the hard-templates and carbohydrates. The chosen cryptomelane hard-templates, which are superior to traditional hard-templates, are converted into Mn3O4 nanoparticles embedded in multiporous CNFs (MCNFs), eliminating the need for tedious post deposition procedures to introduce redox active sites. Hence, the obtained hybrids with large surface areas, hierarchical pores, and unique structures show great potential in supercapacitors. This economic and sustainable strategy paves a new way for synthesizing MCNFs and metal oxide-encapsulated MCNFs composites from biomass.
Co-reporter:Haiyan Jin; Jing Wang; Diefeng Su; Zhongzhe Wei; Zhenfeng Pang
Journal of the American Chemical Society 2015 Volume 137(Issue 7) pp:2688-2694
Publication Date(Web):February 6, 2015
DOI:10.1021/ja5127165
Remarkable hydrogen evolution reaction (HER) or superior oxygen evolution reaction (OER) catalyst has been applied in water splitting, however, utilizing a bifunctional catalyst for simultaneously generating H2 and O2 is still a challenging issue, which is crucial for improving the overall efficiency of water electrolysis. Herein, inspired by the superiority of carbon conductivity, the propitious H atom binding energy of metallic cobalt, and better OER activity of cobalt oxide, we synthesized cobalt–cobalt oxide/N-doped carbon hybrids (CoOx@CN) composed of Co0, CoO, Co3O4 applied to HER and OER by simple one-pot thermal treatment method. CoOx@CN exhibited a small onset potential of 85 mV, low charge-transfer resistance (41 Ω), and considerable stability for HER. Electrocatalytic experiments further indicated the better performance of CoOx@CN for HER can be attributed to the high conductivity of carbon, the synergistic effect of metallic cobalt and cobalt oxide, the stability of carbon-encapsulated Co nanoparticles, and the introduction of electron-rich nitrogen. In addition, when used as catalysts of OER, the CoOx@CN hybrids required 0.26 V overpotential for a current density of 10 mA cm–2, which is comparable even superior to many other non-noble metal catalysts. More importantly, an alkaline electrolyzer that approached ∼20 mA cm–2 at a voltage of 1.55 V was fabricated by applying CoOx@CN as cathode and anode electrocatalyst, which opened new possibilities for exploring overall water splitting catalysts.
Co-reporter:Yutong Gong, Mingming Li, Haoran Li and Yong Wang
Green Chemistry 2015 vol. 17(Issue 2) pp:715-736
Publication Date(Web):06 Nov 2014
DOI:10.1039/C4GC01847H
Due to their industrial indispensability, heterogeneous catalytic oxidation and hydrogenation continue to be topics of great interest in both experimental and theoretical studies. Graphitic carbon nitride (g-C3N4), due to its unique structure and thus excellent properties such as semiconductivity and nitrogen richness, is suitable to act as a metal-free catalyst or catalyst support for these two significant transformations. This critical review will summarize the recent significant advances achieved in the field of oxidation and hydrogenation realized by g-C3N4 based catalytic systems. The review covers the practical applications and brief mechanistic discussions in three broad catalytic cases, catalytic oxidation under light irradiation, catalytic oxidation without light illumination, and catalytic hydrogenation with g-C3N4 supporting metal nanoparticles. The state-of-the-art and future challenges of heterogeneous hydrogenation and oxidation by g-C3N4 based systems are also discussed.
Co-reporter:Jiang Deng, Tianyi Xiong, Fan Xu, Mingming Li, Chuanlong Han, Yutong Gong, Haiyan Wang and Yong Wang
Green Chemistry 2015 vol. 17(Issue 7) pp:4053-4060
Publication Date(Web):02 Jun 2015
DOI:10.1039/C5GC00523J
Hierarchically porous carbons (HPCs) show great potential in energy storage due to their high surface area as well as short ion transport path derived from the interconnected porous framework. However, most existing protocols highly rely on nanocasting and soft-templating, which usually make the use of specific raw materials and thus their industrial application unfeasible. It still remains a big challenge to build HPCs from crude biomass, which is abundant on the earth, through a simple one-pot approach. Inspired by leavening of bread, we design a strategy to fabricate HPCs with three-dimensional (3D) hierarchical pores consisting of macro, meso, and micropores. The “leavening method” is conducted simply by mixing the biomass with KHCO3 followed by elevated temperature treatment. Besides the well-defined hierarchical structure, the as-prepared HPCs also exhibit notably large specific areas (up to 1893 m2 g−1). It is noteworthy that this “leavening” strategy is widely applicable to most of the biomass derivatives and biomass, including glucose, cellulose, chitin, starch, rice straw, bamboo, etc. When evaluated as supercapacitor electrode materials in two-electrode test systems, the as-prepared HPCs exhibit an excellent electrochemical performance: a specific capacitance of 253 F g−1, with almost no capacitance loss after 10000 cycles.
Co-reporter:Minghui Tang, Shanjun Mao, Mingming Li, Zhongzhe Wei, Fan Xu, Haoran Li, and Yong Wang
ACS Catalysis 2015 Volume 5(Issue 5) pp:3100
Publication Date(Web):April 14, 2015
DOI:10.1021/acscatal.5b00037
RuPd alloy nanoparticles (3.6 nm) uniformly dispersed on N-doped carbon (RuPd/CN) was prepared via a simple ultrasound-assisted coreduction method. The RuPd/CN is highly active, selective, and stable in the hydrogenation of benzoic acid to cyclohexanecarboxylic acid under mild conditions with a TOF up to 2066 h–1. It was found that the bimetallic RuPd/CN catalyst exhibited a substantially enhanced activity in comparison with the monometallic catalysts (Ru/CN and Pd/CN). The reason for the higher performance of the RuPd/CN catalyst is considered to be the increased Ru0 /Run+ ratio induced by the electronic interaction between Ru and Pd, as evidenced by various characterizations. Notably, the different phenomenon of activity platform on different catalysts ascribed to the effect of hydrogen pressure was newly observed and further explained by first-principle studies. Moreover, the factors influencing the adsorption modes of BA, especially the configuration of the carboxyl group, have been investigated preliminarily in first-principle studies, giving a distinct insight from the former work. The reason the carboxyl group in benzoic acid does not undergo hydrogenation, which results in superior selectivity (>99%), is also revealed by a comparison of the thermodynamics of hydrogenation and dissociation of the carboxyl group.Keywords: benzoic acid; bimetallic catalyst; chemoselective hydrogenation; N-doped carbon; RuPd alloy
Co-reporter:Zhongzhe Wei, Jing Wang, Shanjun Mao, Diefeng Su, Haiyan Jin, Yihe Wang, Fan Xu, Haoran Li, and Yong Wang
ACS Catalysis 2015 Volume 5(Issue 8) pp:4783
Publication Date(Web):July 3, 2015
DOI:10.1021/acscatal.5b00737
The earth-abundant nanohybrids Co0/Co3O4@N-doped carbon nanotubes were fabricated via an efficient thermal condensation of d-glucosamine hydrochloride, melamine, and Co(NO3)2·6H2O. The hybrids furnish excellent catalytic activity and perfect chemoselectivity (>99%) for a wide range of substituted nitroarenes (21 examples) under relatively mild conditions. The high catalytic performance and durability is attributed to the synergistic effects between each component, the unique structure of graphene layers-coated Co0, and the electronic activation of doped nitrogen. Density functional calculations indicate that the inner Co0 core and N species on the carbon shell can significantly decrease the dissociation energies of H2, giving evidence of the ability of carbon shell in the hybrids to enable H2 activation. These results open up an avenue to design more powerful low-cost catalysts for industrial applications.Keywords: chemoselective hydrogenation; heterogeneous catalyst; metallic cobalt; nitroarenes; nitrogen
Co-reporter:Diefeng Su, Jing wang, Haiyan Jin, Yutong Gong, Mingming Li, Zhenfeng Pang and Yong Wang
Journal of Materials Chemistry A 2015 vol. 3(Issue 22) pp:11756-11761
Publication Date(Web):06 May 2015
DOI:10.1039/C5TA02217G
We report a novel, simple, and one-pot method for the synthesis of ultrafinely dispersed iron oxide based nanoparticles (NPs) embedded in a nitrogen doped carbon matrix (denoted as Fe2O3/Fe@CN). A well-designed iron oxide based hybrid that demonstrates high activity and excellent durability for the HER in alkaline solution has been reported for the first time. The catalyst displays a small Tafel slope of 114 mV per decade and good electrocatalytic stability for 30000 seconds. Detailed electrochemical and physical studies indicate that the high HER activity of the hybrid catalyst results from the strong interaction between Fe-based NPs and N-doped graphitic carbon, and especially the synergistic effect of Fe and Fe2O3.
Co-reporter:Jing Wang, Zhongzhe Wei, Yutong Gong, Shiping Wang, Diefeng Su, Chuanlong Han, Haoran Li and Yong Wang
Chemical Communications 2015 vol. 51(Issue 64) pp:12859-12862
Publication Date(Web):23 Jun 2015
DOI:10.1039/C5CC02593A
Graphitic carbon nanotubes (GCNTs) were fabricated from in situ produced graphitic carbon by calcining biomass/melamine/Ni(NO3)2·6H2O. Ni-based hybrids (NiOx@GCNTs) displayed superior catalytic capacity in direct dehydrogenation of ethylbenzene. The specific reaction rate can reach up to 8.1 μmol m−2 h−1, and unprecedented stability was obtained over 165 h without any activation process.
Co-reporter:Zhongzhe Wei, Yutong Gong, Tianyi Xiong, Pengfei Zhang, Haoran Li and Yong Wang
Catalysis Science & Technology 2015 vol. 5(Issue 1) pp:397-404
Publication Date(Web):18 Aug 2014
DOI:10.1039/C4CY00946K
Palladium nanoparticles supported on N-doped hierarchically porous carbon, Pd/CNx, has been developed as a highly efficient, reusable and environmentally benign heterogeneous catalyst for the selective hydrogenation of various α,β-unsaturated carbonyls to their corresponding saturated carbonyls under mild conditions (303 K, 1 bar H2). Complete conversion of a series of α,β-unsaturated carbonyls was achieved with excellent selectivity (>99%) within 4 h. Moreover, the catalyst can be easily recovered by centrifugation and withstands recycling up to 8 times without apparent loss of activity and selectivity. The considerable catalytic performance is attributed to the hierarchically porous network and incorporation of nitrogen atoms. This catalytic system opens up an efficient, selective, recyclable and sustainable method for selective hydrogenation.
Co-reporter:Yutong Gong;Mingming Li
ChemSusChem 2015 Volume 8( Issue 6) pp:931-946
Publication Date(Web):
DOI:10.1002/cssc.201403287
Abstract
With the explosive growth of energy consumption, the exploration of highly efficient energy conversion and storage devices becomes increasingly important. Fuel cells, supercapacitors, and lithium-ion batteries are among the most promising options. The innovation of these devices mainly resides in the development of high-performance electrode materials and catalysts. Graphitic carbon nitride (g-C3N4), due to structural and chemical properties such as semiconductor optical properties, rich nitrogen content, and tunable porous structure, has drawn considerable attention and shown great potential as an electrode material or catalyst in energy conversion and storage devices. This review covers recent progress in g-C3N4-containing systems for fuel cells, electrocatalytic water splitting devices, supercapacitors, and lithium-ion batteries. The corresponding catalytic mechanisms and future research directions in these areas are also discussed.
Co-reporter:Dr. Shiping Wang;Minglei Zhu;Xiaobing Bao;Jing Wang;Chunhong Chen; Haoran Li ; Yong Wang
ChemCatChem 2015 Volume 7( Issue 18) pp:2937-2944
Publication Date(Web):
DOI:10.1002/cctc.201500293
Abstract
The tedious and costly route of the general nanocasting method hinders the commercial application of mesoporous non-precious metal catalysts based on transition metal-coordinating nitrogen-doped carbons (MN/C). Here, a simple, economic and sustainable hydrothermal carbonization (HTC)/soft templating method is demonstrated for the direct preparation of mesoporous FeN/C materials (FeN/MC). By this method, FeN/MC materials with high specific surface area, hierarchically mesoporous structure, and appropriate iron and nitrogen contents are prepared. The optimized FeN/MC materials exhibit superior catalytic performance in the oxygen reduction reaction (ORR) to commercial Pt/C in 0.1 M KOH. This confirms that the materials are one of the most efficient non-precious metal catalysts for the ORR in alkaline electrolyte. In addition, considerable durability and ORR activity are demonstrated by the FeN/MC materials in 0.1 M HClO4. Thus, this HTC/soft templating method has great promise for the practical application of this kind of non-precious metal catalysts in the ORR.
Co-reporter:Mingming Li, Xuan Xu, Yutong Gong, Zhongzhe Wei, Zhaoyin Hou, Haoran Li and Yong Wang
Green Chemistry 2014 vol. 16(Issue 9) pp:4371-4377
Publication Date(Web):23 Jun 2014
DOI:10.1039/C4GC00850B
A novel and sustainable synthesis of a Pd/CN@MgO catalyst is presented here, offering a bifunctional catalyst with high catalytic activity towards a tandem aldol condensation–hydrogenation reaction of furfural with acetone in a one-pot reactor. The incorporation of biomass based hydrophilic N-containing carbon (CN) in the catalyst provides a subtle but elegant method to control the good water dispersibility, the reaction stability, and the ultrafine dispersion of palladium particles (2.2 nm in average size) in the bifunctional catalyst Pd/CN@MgO. With such improved features, an impressive 99% furfural conversion and 95% selectivity for the hydrogenated products (saturated ketones) was obtained by using Pd/CN@MgO as a novel bifunctional catalyst in the reported tandem reaction. This catalyst design strategy and the high efficiency of the catalyst in the reported system offer potential for the preparation of bi/multifunctional catalysts and the one-pot synthesis of bioderived intermediates.
Co-reporter:Xuan Xu, Minghui Tang, Mingming Li, Haoran Li, and Yong Wang
ACS Catalysis 2014 Volume 4(Issue 9) pp:3132
Publication Date(Web):August 12, 2014
DOI:10.1021/cs500859n
A novel N-doped carbon (CN) was prepared by the hydrothermal method using glucosamine hydrochloride as both carbon and nitrogen precursor, followed by a postsynthesis heat treatment. Pd@CN exhibited 9 times higher activity compared to that of commercial Pd@AC on hydrogenation of benzoic acid to cyclohexanecarboxylic acid. The influence of solvent and substituent were also investigated. Besides, the hydrogenations of various benzoic acids have been carried out over Pd@CN.Keywords: benzoic acid; chemoselective hydrogenation; heterogeneous catalyst; mild condition; N-doped hydrothermal carbon
Co-reporter:Shiping Wang, Chuanlong Han, Jing Wang, Jiang Deng, Minglei Zhu, Jia Yao, Haoran Li, and Yong Wang
Chemistry of Materials 2014 Volume 26(Issue 23) pp:6872
Publication Date(Web):November 20, 2014
DOI:10.1021/cm503669v
Hydrothermal carbonization (HTC) of carbohydrates is an economic and sustainable technique for the synthesis of carbon materials. However, the assembly of carbohydrates with soft templates is susceptible to hydrolysis, degradation, and relatively high HTC temperature. Thus, it is still challenging to control the HTC/soft templating of carbohydrates and prepare mesoporous carbon with specific properties. Herein, a simple and effective self-transformation strategy is proposed to improve the HTC/soft templating, which introduces an insoluble melamine sulfate into the formation processes. Mechanism studies indicate that the assembly of d-fructose with soft templates is greatly promoted by coassembling with the gradually released melamine sulfate. As a result, carbonaceous composites with a flower-like structure and N-doping were synthesized. Further, ordered mesoporous carbons with N-doping are obtained after calcination. The obtained carbons exhibit outstanding ability for heavy metal adsorption and supercapacitors. Significantly, this self-transformation strategy will open up new avenues for synthesizing carbohydrate-based functional carbons.
Co-reporter:Shiping Wang, Ruihan Liu, Chuanlong Han, Jing Wang, Mingming Li, Jia Yao, Haoran Li and Yong Wang
Nanoscale 2014 vol. 6(Issue 22) pp:13510-13517
Publication Date(Web):10 Sep 2014
DOI:10.1039/C4NR03826F
Hydrothermal carbonization (HTC) of carbohydrate is an interesting candidate for the preparation of carbon materials, as it provides an easy, inexpensive and environmental friendly route. However, it is difficult to prepare porous carbon materials by a straight HTC process. Herein, the solubilising technology of micelles was introduced to direct the HTC of fructose by using an amphiphilic block copolymer, poly-(4-vinylpyridine)-block-poly-(ethylene glycol) (P4VP-PEG), as a structure-directing agent. By this strategy, hierarchical porous carbon materials with tunable properties were prepared. It was found that P4VP-PEG micelles could solubilize fructose and confine the formation of primary carbon domains during a sol–gel process. And the micelle size could be adjusted easily by changing the preparation conditions. Accordingly, the particle size of the obtained carbon materials was effectively tuned from 20 to 100 nm by the direction of the primary micelle size. After calcination, the hierarchical porous carbon materials were evidenced as effective electrode materials for supercapacitor with a capacitance of ∼197 F at 1 A g−1, which was almost four times higher than the carbon materials prepared by a straight HTC process.
Co-reporter:Chuanlong Han, Jing Wang, Yutong Gong, Xuan Xu, Haoran Li and Yong Wang
Journal of Materials Chemistry A 2014 vol. 2(Issue 3) pp:605-609
Publication Date(Web):07 Nov 2013
DOI:10.1039/C3TA13757K
Honeycomb-like N-doped hollow carbon hemispheres are synthesized by a facile and versatile process, using ionic liquids as the carbon source. The resulting materials show a unique hollow hemisphere morphology, outstanding electrochemical activity, strong immunity towards methanol crossover and stability superior to the commercial Pt/C catalyst in alkaline medium.
Co-reporter:Haiyan Jin, Tianyi Xiong, Yi Li, Xuan Xu, Mingming Li and Yong Wang
Chemical Communications 2014 vol. 50(Issue 84) pp:12637-12640
Publication Date(Web):29 Aug 2014
DOI:10.1039/C4CC06206J
Pd@N-doped carbon (Pd@CN) exhibited four and two times higher peak current density toward ethanol electrooxidation than Pd@active carbon and Pd@non-nitrogen carbon. Controlled experimental results indicated that the incorporation of nitrogen into the carbon matrix improved the percentage of Pd0 and increased the binding energy of Pd in Pd@CN, and accordingly enhanced the catalytic activity.
Co-reporter:Yutong Gong, Lei Xie, Haoran Li and Yong Wang
Chemical Communications 2014 vol. 50(Issue 84) pp:12633-12636
Publication Date(Web):01 Sep 2014
DOI:10.1039/C4CC04998E
Monodisperse, uniform colloidal carbonaceous spheres were fabricated by the hydrothermal treatment of glucose with the help of a tiny amount of sodium polyacrylate (PAANa). This synthetic strategy is effective at high glucose concentration and for scale-up experiments. The sphere size can be easily tuned by the reaction time, temperature and glucose concentration.
Co-reporter:Pengfei Zhang, Yutong Gong, Zhongzhe Wei, Jing Wang, Zhiyong Zhang, Haoran Li, Sheng Dai, and Yong Wang
ACS Applied Materials & Interfaces 2014 Volume 6(Issue 15) pp:12515
Publication Date(Web):July 8, 2014
DOI:10.1021/am5023682
The development of meaningful ways to transfer biomass into useful materials, more efficient energy carriers, and/or carbon storage deposits is a profound challenge of our days. Herein, an ionothermal carbonization (ITC) method, via treating natural resources (glucose, cellulose, and sugar cane bagesse) in nonmetal ionic liquids (ILs) at ∼200 °C, is established for the fabrication of porous heteroatom-doped carbon materials with high yield. Commercial ILs with bulky bis(trifluoromethylsulfonyl)imide anion or cross-linkable nitrile group were found to be efficient and recyclable templates for porosity control, leading to exciting nanoarchitectures with promising performance in oxygen reduction reaction. The optimized ILs (12 mL) can dissolve and directly convert up to 15 g of glucose into porous carbon materials (SBET: 272 m2/g) one time. This ITC method relies on the synergistic use of structure-directing effect, good biomass solubility, and excellent thermal stability of ILs, and provides a sustainable strategy for exploiting biomass.Keywords: biomass; ionic liquid; ionothermal synthesis; nitrogen-doped carbon; porous carbon; soft template
Co-reporter:Pengfei Zhang, Haoran Li and Yong Wang
Chemical Communications 2014 vol. 50(Issue 48) pp:6312-6315
Publication Date(Web):30 Apr 2014
DOI:10.1039/C4CC02676D
Described here is the feasible modification of a graphitic carbon nitride polymer using Prato's reaction with in situ formed azomethine ylides. These novel carbon nitrides with designable organic functional groups, and tailorable surface and structure properties illustrated excellent performance in the selective oxidation of 3,5,5-trimethylcyclohex-3-en-1-one using atmospheric oxygen.
Co-reporter:Yutong Gong, Haiyan Wang, Zhongzhe Wei, Lei Xie, and Yong Wang
ACS Sustainable Chemistry & Engineering 2014 Volume 2(Issue 10) pp:2435
Publication Date(Web):September 17, 2014
DOI:10.1021/sc500447j
Hydrothermal carbonization of biomass is regarded as the most sustainable technique to fabricate functional carbonaceous materials. The absence of nanoporous structures in the as-obtained materials remains a stumbling block to their wide applications. A hard-templating method and KOH activation are mostly frequently applied to introduce porous structures into HTC materials, but they always suffer from either tedious synthetic processes or massive use of a strong base. Here, the hierarchically porous structure was developed by heat treatment in the static air atmosphere. The textual properties were investigated by TEM and N2 sorption analyses. The structural order and surface chemistry were characterized by XRD, Raman, and XPS. The results show that the activated HTC carbons are rich in micropores and mesopores with high surface areas up to 1704 m2/g. The mesopore volume would reach over 50% of the total pore volume. In addition, these carbons show high performance in CO2 and dye adsorption.Keywords: Air activation; CO2 adsorption; Dye adsorption; High mesopore ratio; Hydrothermal carbonization; Large surface area;
Co-reporter:Haiyan Wang, Yutong Gong and Yong Wang
RSC Advances 2014 vol. 4(Issue 86) pp:45753-45759
Publication Date(Web):05 Sep 2014
DOI:10.1039/C4RA08446B
Carbon aerogels have attracted considerable attention in fundamental investigation and potential applications in a myriad of fields. We present a novel approach for the synthesis of cellulose-based carbon aerogels by dissolution, gelation, regeneration, freeze-drying and carbonization of cellulose. The carbon aerogels obtained here possess the characteristics of high surface area (500 m2 g−1), hydrophobicity, and fire-resistance. In addition, the carbon aerogels show excellent adsorption capacity and selectivity for removal of oils, organic solvents, a variety of dyes, and heavy ions, so they could be used as promising adsorbents for sewage treatment. Especially for malachite green and Cu(II), the adsorption capacities can reach up to 1947 mg g−1 and 801 mg g−1, respectively, which far surpass other aerogels previous reported.
Co-reporter:Jing Wang;Dr. Zheng Xu;Yutong Gong;Chuanlong Han;Dr. Haoran Li;Dr. Yong Wang
ChemCatChem 2014 Volume 6( Issue 5) pp:1204-1209
Publication Date(Web):
DOI:10.1002/cctc.201301102
Abstract
Oxidized sulfur and nitrogen co-doped graphitic carbon (SN-G) was one-step synthesized simply by annealing a solid mixture of D-glucosamine hydrochloride, melamine, and trithiocyanuric acid. By tailoring the additive dosage and the pyrolysis temperature, correlations between the structure, composition, and electrochemical performance of SN-G were systematically elucidated. To our excitement, the SN3-G sample pyrolyzed at 900 °C with a dominant oxidized sulfur content exhibited striking electrocatalytic activity in alkaline medium, which was free from the crossover effect, and its long-term durability was superior to that of commercial Pt/C (20 wt %). Furthermore, oxidized sulfur that was reported to be chemically inactive for the ORR was proven to be active, which was supported by both experimental results and density functional theory calculations.
Co-reporter:Xuan Xu;Dr. Haoran Li ;Dr. Yong Wang
ChemCatChem 2014 Volume 6( Issue 12) pp:3328-3332
Publication Date(Web):
DOI:10.1002/cctc.201402561
Abstract
In this report, a kind of mesoporous N-doped carbon (CN-x) derived from N-containing ionic-liquid (IL) precursors were synthesized, and Pd@CN-x prepared by a simple ultrasound-assisted method showed higher catalytic activity for the selective hydrogenation of phenol and its derivatives under mild reaction conditions in water than commercial Pd@C and other common Pd heterogeneous catalysts. The catalytic activities of Pd@CN-x derived from different ILs were different, and further study into the influencing factors, including physical properties, N species of CN-x, and Pd status of Pd@CN-x, were performed.
Co-reporter:Yutong Gong;Jing Wang;Zhongzhe Wei;Pengfei Zhang;Haoran Li
ChemSusChem 2014 Volume 7( Issue 8) pp:2303-2309
Publication Date(Web):
DOI:10.1002/cssc.201402078
Abstract
Due to their versatile features and environmental friendliness, functionalized carbon materials show great potential in practical applications, especially in energy conversion. Developing carbon composites with properties that can be modulated by simply changing the ratio of the original materials is an intriguing synthetic strategy. Here, we took cyanamide and multiwalled carbon nanotubes as precursors and introduced a facile method to fabricate a series of graphitic carbon nitride/carbon nanotubes (g-C3N4/CNTs) composites. These composites demonstrated different practical applications with different weight ratios of the components, that is, they showed synergistic effects in optoelectronic conversion when g-C3N4 was the main ingredient and in oxygen reduction reaction (ORR) when CNTs dominated the composites. Our experiments indicated that the high electrical conductivity of carbon nanotubes promoted the transmission of the charges in both cases.
Co-reporter:Chuanlong Han;Shiping Wang;Jing Wang;Mingming Li;Jiang Deng;Haoran Li
Nano Research 2014 Volume 7( Issue 12) pp:1809-1819
Publication Date(Web):2014 December
DOI:10.1007/s12274-014-0540-x
Encompassing ecological and economic concerns, the utilization of biomass to produce carbonaceous materials has attracted intensive research and industrial interest. Using nitrogen containing precursors could realize an in situ and homogeneous incorporation of nitrogen into the carbonaceous materials with a controlled process. Herein, N-doped hollow core-disordered mesoporous shell carbonaceous nanospheres (HCDMSs) were synthesized from glucosamine hydrochloride (GAH), an applicable carbohydrate-based derivative. The obtained HCDMSs possessed controlled size (∼450-50 nm) and shell thickness (∼70-10 nm), suitable nitrogen contents (∼6.7-4.4 wt.%), and Brunauer-Emmett-Teller (BET) surface areas up to 770 m2·g−1. These materials show excellent electrocatalytic activity as a metal-free catalyst for the oxygen reduction reaction (ORR) in both alkaline and acidic media. Specifically, the prepared HCDMS-1 exhibits a high diffusion-limited current, and superior durability and better immunity towards methanol crossover and CO poisoning for ORR in alkaline solution than a commercial 20 wt.% Pt/C catalyst.
Co-reporter:Dongshun Deng, Yang Yang, Yutong Gong, Yi Li, Xuan Xu and Yong Wang
Green Chemistry 2013 vol. 15(Issue 9) pp:2525-2531
Publication Date(Web):26 Jun 2013
DOI:10.1039/C3GC40779A
Palladium nanoparticles supported on a mesoporous graphitic carbon nitride, Pd@mpg-C3N4, has been developed as an effective, heterogeneous catalyst for the liquid-phase semihydrogenation of phenylacetylene under mild conditions (303 K, atmospheric H2). A total conversion was achieved with high selectivity of styrene (higher than 94%) within 85 minutes. Moreover, the spent catalyst can be easily recovered by filtration and then reused nine times without apparent lose of selectivity. The generality of Pd@mpg-C3N4 catalyst for partial hydrogenation of alkynes was also checked for terminal and internal alkynes with similar performance. The Pd@mpg-C3N4 catalyst was proven to be of industrial interest.
Co-reporter:Pengfei Zhang, Yutong Gong, Haoran Li, Zhirong Chen and Yong Wang
RSC Advances 2013 vol. 3(Issue 15) pp:5121-5126
Publication Date(Web):07 Feb 2013
DOI:10.1039/C3RA23357J
Existing phenol production mostly by cumene processes is a three-step route with unwanted acetone as by-product. Here, we report the FeCl3 and mesoporous carbon nitride hybrid (FeCl3/mpg-C3N4) as an active and selective photocatalyst to activate H2O2 for the oxidation of benzene to phenol under visible-light illumination. By fine-optimizing FeCl3 loading amount in catalyst and reaction conditions, the one-step process achieved a 38% benzene conversion with 97% selectivity for phenol. The excellent catalytic performance of FeCl3/mpg-C3N4 should be attributed to the fast reduction of Fe3+ to Fe2+ by photo-irradiated electrons from mpg-C3N4. To further understand the reaction route, several electron spin resonance (ESR) tests were carried out, confirming mpg-C3N4 promoted redox cycle of Fe2+/Fe3+ in the FeCl3/mpg-C3N4 system. Based on these results, a catalytic mechanism for the oxidation of benzene by FeCl3/mpg-C3N4 hybrids was provided. This environmental-friendly and efficient method is expected to open up a new avenue for one-step phenol preparation.
Co-reporter:Pengfei Zhang, Jiayin Yuan, Haoran Li, Xiaofeng Liu, Xuan Xu, Markus Antonietti and Yong Wang
RSC Advances 2013 vol. 3(Issue 6) pp:1890-1895
Publication Date(Web):27 Nov 2012
DOI:10.1039/C2RA22559J
Copper-driven Ullmann-type cross-coupling reactions are regarded as one of the most important methods for the C–O, C–N, C–S and some other bonds formation. Herein, we report that mesoporous nitrogen-doped carbon materials with high nitrogen content function as novel, active and recyclable N-type heterogeneous promoters for copper-catalyzed cross-couplings. By using CuI as the catalyst and a mesoporous nitrogen-doped carbon material as the promoter, the Ullmann-type coupling reactions of various aryl halides with phenols, amines, imidazol, and thiophenols at 100 °C gave the corresponding products in good yields. Inspired by the efficiency of mesoporous nitrogen-doped carbon material as a promoter, nitrogen-doped carbon supported CuO nanoparticles are prepared and successfully employed as efficient heterogeneous catalysts in the C–O cross-coupling reactions. Furthermore, the nitrogen-doped carbon material supported CuO can be simply recycled by centrifugation and reused at least four times with trace copper leaching. The mesoporous nitrogen-doped carbon materials as heterogeneous promoters or copper-based catalyst supports may represent a promising catalyst system in modern Ullmann chemistry, which indeed could lead to improved processing steps.
Co-reporter:Yi Li, Xuan Xu, Pengfei Zhang, Yutong Gong, Haoran Li and Yong Wang
RSC Advances 2013 vol. 3(Issue 27) pp:10973-10982
Publication Date(Web):12 Apr 2013
DOI:10.1039/C3RA41397G
The liquid phase selective hydrogenation of phenol to cyclohexanone has been investigated over polymeric mesoporous graphitic carbon nitride (mpg–C3N4) supported Pd catalysts (Pd@mpg-C3N4). This Pd@mpg-C3N4 is shown to be highly active and promotes the selective formation of cyclohexanone (∼99%), an industrially important compound, in a “one-step” method. The effects of different variables like solvent, reaction temperature, catalyst texture and catalyst pre-treatment are presented and discussed. The different adsorption capacity of mpg–C3N4 between the phenol and cyclohexanone is suggested to strongly promote the chemoselective reduction of phenol to cyclohexanone and avoid the deep hydrogenation of cyclohexanone to cyclohexanol. The hydrogenation kinetics has been adequately represented by a standard pseudo-first-order approximation, and isotopic tracing study and the transition state calculation were applied for the discussion of the possible reaction mechanism.
Co-reporter:Pengfei Zhang;Dr. Jiayin Yuan;Dr. Tim-Patrick Fellinger;Dr. Markus Antonietti;Dr. Haoran Li;Dr. Yong Wang
Angewandte Chemie International Edition 2013 Volume 52( Issue 23) pp:6028-6032
Publication Date(Web):
DOI:10.1002/anie.201301069
Co-reporter:Pengfei Zhang;Dr. Jiayin Yuan;Dr. Tim-Patrick Fellinger;Dr. Markus Antonietti;Dr. Haoran Li;Dr. Yong Wang
Angewandte Chemie International Edition 2013 Volume 52( Issue 23) pp:
Publication Date(Web):
DOI:10.1002/anie.201303272
Co-reporter:Xuan Xu ; Yi Li ; Yutong Gong ; Pengfei Zhang ; Haoran Li
Journal of the American Chemical Society 2012 Volume 134(Issue 41) pp:16987-16990
Publication Date(Web):October 3, 2012
DOI:10.1021/ja308139s
We report a catalyst made of Pd nanoparticles (NPs) supported on mesoporous N-doped carbon, Pd@CN0132, which was shown to be highly active in promoting biomass refining. The use of a task-specific ionic liquid (3-methyl-1-butylpyridine dicyanamide) as a precursor and silica NPs as a hard template afforded a high-nitrogen-content (12 wt %) mesoporous carbon material that showed high activity in stabilizing Pd NPs. The resulting Pd@CN0.132 catalyst showed very high catalytic activity in hydrodeoxygenation of vanillin (a typical model compound of lignin) at low H2 pressure under mild conditions in aqueous media. Excellent catalytic results (100% conversion of vanillin and 100% selectivity for 2-methoxy-4-methylphenol) were achieved, and no loss of catalytic activity was observed after six recycles.
Co-reporter:Pengfei Zhang, Yong Wang, Haoran Li and Markus Antonietti
Green Chemistry 2012 vol. 14(Issue 7) pp:1904-1908
Publication Date(Web):10 May 2012
DOI:10.1039/C2GC35148J
Mesoporous graphitic carbon nitride (mpg-C3N4) has been developed as a non-metal, heterogeneous photocatalyst for the selective oxidation of sulfides to sulfoxides with O2 at room temperature. Especially, the combination of mpg-C3N4 and aldehydes was a highly active system under visible-light irradiation. For example, mpg-C3N4/isobutyraldehyde catalytic oxidation of methyl phenyl sulfide afforded 97% conversion with 98% selectivity for the methyl phenyl sulfoxide in 4 h. Moreover, the mpg-C3N4 can be easily recovered by filtration and then reused at least four times without losing activity. By exploring the electron spin resonance and some comparative experiments, a catalytic mechanism of this oxidation was provided. Finally, the system also works well in the oxidation of a number of sulfides, including sulfides bearing various groups, and phenyl disulfide. The use of a metal-free heterogeneous catalyst and visible light energy, along with the mild reaction conditions makes this oxidation reaction an environmentally benign and energy-saving chemical process.
Co-reporter:Yong Wang ; Jia Yao ; Haoran Li ; Dangsheng Su ;Markus Antonietti
Journal of the American Chemical Society 2011 Volume 133(Issue 8) pp:2362-2365
Publication Date(Web):February 4, 2011
DOI:10.1021/ja109856y
Cyclohexanone is an important intermediate in the manufacture of polyamides in chemical industry, but direct selective hydrogenation of phenol to cyclohexanone under mild conditions is a challenge. We report here a catalyst made of Pd nanoparticles supported on a mesoporous graphitic carbon nitride, Pd@mpg-C3N4, which was shown to be highly active and promoted the selective formation of cyclohexanone under atmospheric pressure of hydrogen in aqueous media without additives. Conversion of 99% and a selectivity higher than 99% were achieved within 2 h at 65 °C. The reaction can be accelerated at higher temperature, but even at room temperature, 99% conversion and 96% selectivity could still be obtained. The generality of the Pd@mpg-C3N4 catalyst for this reaction was demonstrated by selective hydrogenation of other hydroxylated aromatic compounds with similar performance.
Co-reporter:Yong Wang, Yan Di, Markus Antonietti, Haoran Li, Xiufang Chen, and Xinchen Wang
Chemistry of Materials 2010 Volume 22(Issue 18) pp:5119
Publication Date(Web):August 31, 2010
DOI:10.1021/cm1019102
Co-reporter:Yong Wang Dr.;Jinshui Zhang;Xinchen Wang Dr.;Markus Antonietti Dr.;Haoran Li Dr.
Angewandte Chemie 2010 Volume 122( Issue 19) pp:3428-3431
Publication Date(Web):
DOI:10.1002/ange.201000120
Co-reporter:Yong Wang Dr.;Jinshui Zhang;Xinchen Wang Dr.;Markus Antonietti Dr.;Haoran Li Dr.
Angewandte Chemie International Edition 2010 Volume 49( Issue 19) pp:3356-3359
Publication Date(Web):
DOI:10.1002/anie.201000120
Co-reporter:Haiyan Wang, Jiang Deng, Chunmei Xu, Yiqing Chen, Fan Xu, Jing Wang, Yong Wang
Energy Storage Materials (April 2017) Volume 7() pp:216-221
Publication Date(Web):1 April 2017
DOI:10.1016/j.ensm.2017.03.002
Most advances towards flexible supercapacitors (SCs) have been focused on porous carbon materials. However, the poor flexibility and low areal capacitance impede their industrial application. While carbon cloth is generally regarded as improper electrode material due to its poor electrochemical performance, here, we demonstrate the capacitance of carbon cloth can be boosted to three orders of magnitude higher (2900 mF cm-2) with a simple high-temperature annealing process. The improvement stems from ultramicropores effects in the range of 0.46–0.64 nm besides superhydrophilicity and high specific surface area. Remarkably, direct implementation for flexible solid-state SCs (SSCs) provides areal capacitance and energy density for the stack of 920 mF cm-2 and 128 μW h cm-2, respectively. In addition, these devices are bendable, durable and easy to be any dimensions, hence, holding great promise for large-scale production of flexible electronics.Download high-res image (211KB)Download full-size image
Co-reporter:Shiping Wang; Jing Wang; Minglei Zhu; Xiaobing Bao; Bingyang Xiao; Diefeng Su; Haoran Li
Journal of the American Chemical Society () pp:
Publication Date(Web):December 1, 2015
DOI:10.1021/jacs.5b07924
Despite being promising substitutes for noble metal catalysts used in hydrogen evolution reaction (HER), the nonprecious metal catalysts (NPMCs) based on inexpensive and earth-abundant 3d transition metals (TMs) are still practically unfeasible due mainly to unsatisfactory activity and durability. Herein, a highly active and stable catalyst for HER has been developed on the basis of molybdenum-carbide-modified N-doped carbon vesicle encapsulating Ni nanoparticles (MoxC-Ni@NCV). This MoxC-Ni@NCV material was synthesized simply by the solid-state thermolysis of melamine-related composites of oxalate and molybdate with uniform Ni ions doping (Ni@MOM-com). Notably, the prepared MoxC-Ni@NCV was almost the most efficient NPMCs for HER in acidic electrolyte to date. Besides good long-term stability, MoxC-Ni@NCV exhibited a quiet low overpotential that was comparable to Pt/C. Thus, this work opens a new avenue toward the development of highly efficient, inexpensive HER catalysts.
Co-reporter:Jing Wang, Zhongzhe Wei, Yutong Gong, Shiping Wang, Diefeng Su, Chuanlong Han, Haoran Li and Yong Wang
Chemical Communications 2015 - vol. 51(Issue 64) pp:NaN12862-12862
Publication Date(Web):2015/06/23
DOI:10.1039/C5CC02593A
Graphitic carbon nanotubes (GCNTs) were fabricated from in situ produced graphitic carbon by calcining biomass/melamine/Ni(NO3)2·6H2O. Ni-based hybrids (NiOx@GCNTs) displayed superior catalytic capacity in direct dehydrogenation of ethylbenzene. The specific reaction rate can reach up to 8.1 μmol m−2 h−1, and unprecedented stability was obtained over 165 h without any activation process.
Co-reporter:Pengfei Zhang, Haoran Li and Yong Wang
Chemical Communications 2014 - vol. 50(Issue 48) pp:NaN6315-6315
Publication Date(Web):2014/04/30
DOI:10.1039/C4CC02676D
Described here is the feasible modification of a graphitic carbon nitride polymer using Prato's reaction with in situ formed azomethine ylides. These novel carbon nitrides with designable organic functional groups, and tailorable surface and structure properties illustrated excellent performance in the selective oxidation of 3,5,5-trimethylcyclohex-3-en-1-one using atmospheric oxygen.
Co-reporter:Chuanlong Han, Jing Wang, Yutong Gong, Xuan Xu, Haoran Li and Yong Wang
Journal of Materials Chemistry A 2014 - vol. 2(Issue 3) pp:NaN609-609
Publication Date(Web):2013/11/07
DOI:10.1039/C3TA13757K
Honeycomb-like N-doped hollow carbon hemispheres are synthesized by a facile and versatile process, using ionic liquids as the carbon source. The resulting materials show a unique hollow hemisphere morphology, outstanding electrochemical activity, strong immunity towards methanol crossover and stability superior to the commercial Pt/C catalyst in alkaline medium.
Co-reporter:Jing Wang, Zhongzhe Wei, Haiyan Wang, Yiqing Chen and Yong Wang
Journal of Materials Chemistry A 2017 - vol. 5(Issue 21) pp:NaN10516-10516
Publication Date(Web):2017/04/29
DOI:10.1039/C7TA02115A
Water splitting is the mainstay of contemporary energy conversion and storage engineering. The design of earth-abundant electrode materials without extra binders for an efficient hydrogen evolution reaction (HER) is critical in realizing the hydrogen economy in the push for future sustainable development. Herein, three-dimensional (3D) porous electrodes (denoted CoOx–CNT–CC) featuring CoOx nanoparticles (NPs) and carbon nanotubes (CNT) growing on activated carbon fiber were synthesized through a one-pot pyrolysis process. The achieved 3D electrodes acted as efficient electrocatalysts as well as current collectors for hydrogen production, greatly simplifying the electrode preparation process. Impressively, the electrodes exhibited high current density under low overpotential. The current density can reach up to ∼720 mA cm−2, an overpotential of ∼99 mV is required to reach a current density of 20 mA cm−2, and they function with a durability of up to 70 h. Beyond that, the electrodes still show superb catalytic properties at low temperature (the current density is 326 mA cm−2 even at 278 K) and in a neutral medium (the current density is 450 mA cm−2 in 1 M PBS).
Co-reporter:Diefeng Su, Jing wang, Haiyan Jin, Yutong Gong, Mingming Li, Zhenfeng Pang and Yong Wang
Journal of Materials Chemistry A 2015 - vol. 3(Issue 22) pp:NaN11761-11761
Publication Date(Web):2015/05/06
DOI:10.1039/C5TA02217G
We report a novel, simple, and one-pot method for the synthesis of ultrafinely dispersed iron oxide based nanoparticles (NPs) embedded in a nitrogen doped carbon matrix (denoted as Fe2O3/Fe@CN). A well-designed iron oxide based hybrid that demonstrates high activity and excellent durability for the HER in alkaline solution has been reported for the first time. The catalyst displays a small Tafel slope of 114 mV per decade and good electrocatalytic stability for 30000 seconds. Detailed electrochemical and physical studies indicate that the high HER activity of the hybrid catalyst results from the strong interaction between Fe-based NPs and N-doped graphitic carbon, and especially the synergistic effect of Fe and Fe2O3.
Co-reporter:Haiyan Jin, Tianyi Xiong, Yi Li, Xuan Xu, Mingming Li and Yong Wang
Chemical Communications 2014 - vol. 50(Issue 84) pp:NaN12640-12640
Publication Date(Web):2014/08/29
DOI:10.1039/C4CC06206J
Pd@N-doped carbon (Pd@CN) exhibited four and two times higher peak current density toward ethanol electrooxidation than Pd@active carbon and Pd@non-nitrogen carbon. Controlled experimental results indicated that the incorporation of nitrogen into the carbon matrix improved the percentage of Pd0 and increased the binding energy of Pd in Pd@CN, and accordingly enhanced the catalytic activity.
Co-reporter:Yutong Gong, Lei Xie, Haoran Li and Yong Wang
Chemical Communications 2014 - vol. 50(Issue 84) pp:NaN12636-12636
Publication Date(Web):2014/09/01
DOI:10.1039/C4CC04998E
Monodisperse, uniform colloidal carbonaceous spheres were fabricated by the hydrothermal treatment of glucose with the help of a tiny amount of sodium polyacrylate (PAANa). This synthetic strategy is effective at high glucose concentration and for scale-up experiments. The sphere size can be easily tuned by the reaction time, temperature and glucose concentration.
Co-reporter:Zhongzhe Wei, Yutong Gong, Tianyi Xiong, Pengfei Zhang, Haoran Li and Yong Wang
Catalysis Science & Technology (2011-Present) 2015 - vol. 5(Issue 1) pp:NaN404-404
Publication Date(Web):2014/08/18
DOI:10.1039/C4CY00946K
Palladium nanoparticles supported on N-doped hierarchically porous carbon, Pd/CNx, has been developed as a highly efficient, reusable and environmentally benign heterogeneous catalyst for the selective hydrogenation of various α,β-unsaturated carbonyls to their corresponding saturated carbonyls under mild conditions (303 K, 1 bar H2). Complete conversion of a series of α,β-unsaturated carbonyls was achieved with excellent selectivity (>99%) within 4 h. Moreover, the catalyst can be easily recovered by centrifugation and withstands recycling up to 8 times without apparent loss of activity and selectivity. The considerable catalytic performance is attributed to the hierarchically porous network and incorporation of nitrogen atoms. This catalytic system opens up an efficient, selective, recyclable and sustainable method for selective hydrogenation.
Co-reporter:Diefeng Su, Zhongzhe Wei, Shanjun Mao, Jing Wang, Yi Li, Haoran Li, Zhirong Chen and Yong Wang
Catalysis Science & Technology (2011-Present) 2016 - vol. 6(Issue 12) pp:NaN4510-4510
Publication Date(Web):2016/02/02
DOI:10.1039/C5CY02171E
Efficient and inexpensive catalysts are urgently desired for the hydrogenation of 2,3,5-trimethylbenzoquinone (TMBQ) to 2,3,5-trimethylhydroquinone (TMHQ), a key vitamin-E intermediate. In this study, a one-step method was developed to synthesize uniform cobalt-based NPs supported on porous nitrogen-doped carbon for the hydrogenation of TMBQ to TMHQ. The as-prepared catalyst shows a high yield (>90%) and selectivity (>99%) for TMBQ hydrogenation as well as α,β-unsaturated carbonyls. The satisfactory performance is attributed to the small particle size and homogeneous distribution. Meanwhile, metallic Co is proved to be responsible for the catalytic activity. Furthermore, density functional theory calculation discloses that the excellent chemoselectivity towards TMBQ is due to the preference for a desorption process over sequential hydrogenation of TMHQ. This novel material has great potential as a non-precious-metal catalyst for heterogeneous hydrogenation processes, due to its outstanding catalytic performance, simple preparation method and low production cost.
Co-reporter:Mingming Li, Fan Xu, Haoran Li and Yong Wang
Catalysis Science & Technology (2011-Present) 2016 - vol. 6(Issue 11) pp:NaN3693-3693
Publication Date(Web):2016/04/01
DOI:10.1039/C6CY00544F
Developing novel and efficient catalysts is a critical step in common heterogeneous hydrogenation and oxidation reactions. Despite the frequent study of metal oxide-supported catalysts, porous carbon materials have also emerged as valuable potential catalysts. However, due to their highly microporous structures and inferior structural functionalities, traditional activated carbons (ACs) have become increasingly less popular for industrial applications. To deal with the disadvantages of ACs, tremendous efforts have been made to develop novel nitrogen-doped porous carbon (NPC) materials with novel features such as highly porous structures and abundant structural nitrogen heteroatom decoration. As catalysts or catalysts supports, NPC materials have shown superior activities in many applications covering a wide range of heterogeneous hydrogenation and oxidation reactions. In this contribution, we review the fabrication methods for NPC materials used in heterogeneous hydrogenations and oxidations and highlight the intrinsic catalytic mechanisms along with the catalyst design strategies.
Co-reporter:Haiyan Jin, Shanjun Mao, Guopeng Zhan, Fan Xu, Xiaobing Bao and Yong Wang
Journal of Materials Chemistry A 2017 - vol. 5(Issue 3) pp:NaN1084-1084
Publication Date(Web):2016/12/01
DOI:10.1039/C6TA09959A
Cost-effective and highly active electrocatalysts for the oxygen evolution reaction (OER) are critical to energy conversion and storage processes. Herein, a superior OER catalyst of Fe substituted α-Co(OH)2 (α-Co1−mFem(OH)2) has been synthesized by taking advantage of the large layered structure and good conductivity of α-Co(OH)2, in conjunction with the rich redox properties and abundance of Fe. The atomically layered α-Co4Fe(OH)x (Co/Fe = 4) nanoplates could effectively catalyze water oxidation at the onset potential of 0.26 V and its turnover frequency (TOF) was 11 and 5 times higher than those of α-Co(OH)2 and IrO2, respectively. The increased activity could be attributed to strong electronic interactions between Co and Fe. Density functional theory (DFT) calculations also demonstrated that the theoretical overpotential of α-Co1−mFem(OH)2 is obviously lower than that of α-Co(OH)2 and thus Fe doped α-Co(OH)2 displays a better activity. Moreover, the correlation between the Fe content and activity could be plotted as a volcano curve.
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