Co-reporter:Weichen Du;Shuixin Xia;Renfeng Nie
Industrial & Engineering Chemistry Research March 26, 2014 Volume 53(Issue 12) pp:4589-4594
Publication Date(Web):2017-2-22
DOI:10.1021/ie4041719
Surfactant-free, H2-reduced Pt NPs were successfully fabricated on the surface of Fe3O4. Characterizations disclosed that Pt NPs (3.1 nm on average) dispersed evenly on Fe3O4. This catalyst is extremely active and selective for hydrogenation of chloronitrobenzenes, convenient, and suitable for cyclic utilization. The study showed that the activity of Pt depended mainly on its particle size and that the Fe3O4 support is most favorable for this reaction.
Co-reporter:Liping Zheng, Xuewen Li, Weichen Du, Danwei Shi, Wensheng Ning, Xiuyang Lu, Zhaoyin Hou
Applied Catalysis B: Environmental 2017 Volume 203(Volume 203) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.apcatb.2016.10.011
•ZnO decorated Cu particles were synthesized via Cu(Zn)-HKUST-1 precursors.•ZnO decorated Cu catalyst was highly active and stable for hydrogenolysis of glycerol.•The interfacial area between Cu and ZnO played a crucial role on the performance of Cu/ZnO.Cu/ZnO catalysts are widely used in industrial production, environmental protection and biorefinery, finding a new and efficient method for the controlled synthesis of Cu/ZnO hybrid is of great importance. In this work, a novel Cu/ZnO catalyst with nano sized ZnO particles dotted on Cu was synthesized via the calcination and reduction of Cu(Zn)-HKUST-1 precursor. The transformation process from Cu(Zn)-HKUST-1 to Cu/ZnO was characterized by TG-DSC, XRD, XPS and TEM. And the performance of final Cu/ZnO catalysts for continuous hydrogenolysis of glycerol was tested in a fixed-bed reactor. It was found that Cu1.1/ZnO catalyst derived from Cu1.1Zn1.9(BTC)2·9.4(H2O) was more active and stable than Cu/ZnO that prepared via solvent-free grinding and co-precipitation. Characterizations results also inferred that the interface between Cu and ZnO played a crucial role on its catalytic performance, and ZnO dotted Cu was more stable than ZnO plate supported Cu particles.Download high-res image (212KB)Download full-size image
Co-reporter:Mengyuan Zhang, Juanjuan Shi, Wensheng Ning, Zhaoyin Hou
Catalysis Today 2017 Volume 298(Volume 298) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.cattod.2017.04.013
•RGO was a superior support for the growth of ultrafine PtCo NPs.•The dispersion of Pt can be further improved by alloying Pt with Co.•PtCo/RGO exhibited significant performance for the oxidation of glycerol.•PtCo NPs was more aggregation-resisted than monometallic Pt on RGO.Highly dispersed PtCo bimetallic nanoparticles (NPs) were fabricated on reduced graphene oxide (RGO) through microwave irradiation. These PtCo bimetallic NPs showed significantly improved performance for the oxidation of glycerol compared to that of Pt/RGO and Co/RGO. Both the conversion of glycerol (70.2%) and the selectivity of free glyceric acid (GLYA, 85.9%) over PtCo/RGO were obviously higher than that of monometallic Pt/RGO and Co/RGO. Characterizations disclosed that RGO was a superior support for the growth of ultrafine Pt-based NPs, and the dispersion of Pt can be further improved by doping Pt with Co. Moreover, PtCo bimetallic NPs were more aggregation-resisted in comparison to monometallic Pt on the surface of RGO, and it can be reused for 5 runs without obvious deactivation. It was concluded that the strong electrical interaction between Pt and Co in PtCo/RGO might accelerate the oxidation of glycerol, and bimetallic PtCo can hinder the further oxidation of intermediates to C1 byproducts, and thus accelerate the conversion of glycerol and increase the selectivity toward GLYA.Download high-res image (123KB)Download full-size image
Co-reporter:Lihua Yang, Xuewen Li, Yanyan Sun, Linhai Yue, Jie Fu, Xiuyang Lu, Zhaoyin Hou
Catalysis Communications 2017 Volume 101(Volume 101) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.catcom.2017.08.008
•N-doped carbon film was prepared via direct pyrolysis of PVP and urea on a commercial carbon (XC-72).•NxC-XC-72 possesses higher surface area and meso pore channels.•N-dopant can improve the dispersion of Pt and donor electron capacity to Pt.•Pt/NxC-XC-72 was more active and stable for the selective oxidation of glycerol.A series of N-doped carbon film coated active carbon (NxC-XC-72) was prepared via direct pyrolysis of mixed XC-72 (a commercial activated carbon), polyvinyl pyrrolidone and urea. Characterizations indicated that the specific area of synthesized N2.5C-XC-72 reached 281 m2/g and uniform meso pore channels (sized in 4.0 nm) formed. It was found that NxC-XC-72 was an excellent support for the evenly dispersion of Pt compared with raw XC-72. Pt/NxC-XC-72 was active and stable for the selective oxidation of glycerol to glyceric acid in a base-free aqueous solution. The calculated turnover frequency on the basis of surface Pt increased from 573 (in Pt/XC-72) to 706 h− 1 (in Pt/N2.5C-XC-72) at 60 °C.N-doped carbon film coated active carbon (NxC-XC-72) possesses higher surface area and meso pore channels, and Pt/NxC-XC-72 was more active and stable for the selective oxidation of glycerol.Download high-res image (475KB)Download full-size image
Co-reporter:Yanyan Sun, Xuewen Li, Jianguo Wang, Wensheng Ning, Jie Fu, Xiuyang Lu, Zhaoyin Hou
Applied Catalysis B: Environmental 2017 Volume 218(Volume 218) pp:
Publication Date(Web):5 December 2017
DOI:10.1016/j.apcatb.2017.06.086
•Carbon film encapsulated Pt NPs over MWCNTs was prepared via thermal treatment of Pt/MWCNTs in H2.•Carbon film encapsulated Pt NPs was more active and stable than bare Pt for alcohols oxidation.•Carbon film encapsulation can overcome the sintering, leaching, and over-oxidation of Pt NPs.•Carbon film can also prevent the strong adsorption of organic carboxylic acid on Pt surface.Platinum is one of the best catalysts for various applications, but the deactivation of Pt nanoparticles (NPs) during alcohol oxidation is a major barrier to commercialization. In this work, multiwall carbon nanotubes supported carbon film encapsulated Pt NPs (Pt@C-MWCNTs) was synthesized and used in the selective oxidation of ethanol and glycerol in acidic aqueous solution. It was found that Pt@C-MWCNTs exhibited both higher activity and stability than bare Pt NPs. Characterization indicated that carbon film encapsulation can overcome the sintering, leaching and over-oxidation of Pt NPs during the reaction. Moreover, carbon film may also prevent the strong adsorption of organic carboxylic acid on Pt.Download high-res image (105KB)Download full-size image
Co-reporter:Juanjuan Shi, Mengsi Zhao, Yingyu Wang, Jie Fu, Xiuyang Lu and Zhaoyin Hou
Journal of Materials Chemistry A 2016 vol. 4(Issue 16) pp:5842-5848
Publication Date(Web):22 Mar 2016
DOI:10.1039/C6TA01317A
Fast pyrolysis of biomass for bio-oil production is a direct route to renewable liquid fuels, but raw bio-oil must be upgraded in order to remove easily polymerized compounds (such as phenols and furfurals). Herein, a synthesis strategy for graphene encapsulated Ru nanoparticles (NPs) on carbon sheets (denoted as Ru@G-CS) and their excellent performance for the upgrading of raw bio-oil were reported. Ru@G-CS composites were prepared via the direct pyrolysis of mixed glucose, melamine and RuCl3 at varied temperatures (500–800 °C). Characterization indicated that very fine Ru NPs (2.5 ± 1.0 nm) that were encapsulated within 1–2 layered N-doped graphene were fabricated on N-doped carbon sheets (CS) in Ru@G-CS-700 (pyrolysis at 700 °C). And the Ru@G-CS-700 composite was highly active and stable for hydrogenation of unstable components in bio-oil (31 samples including phenols, furfurals and aromatics) even in aqueous media under mild conditions. This work provides a new protocol to the utilization of biomass, especially for the upgrading of bio-oil.
Co-reporter:Juanjuan Shi, Yingyu Wang, Weichen Du, Zhaoyin Hou
Carbon 2016 Volume 99() pp:330-337
Publication Date(Web):April 2016
DOI:10.1016/j.carbon.2015.12.049
The design and facile synthesis of versatile, non-noble metal catalysts with high activity and stability is extremely important for industrial applications. Herein, a novel, simple and one-pot approach of controlled synthesis of graphene encapsulated Fe3C that embedded in carbon nanotubes (denoted as Fe3C@G-CNT) via direct pyrolysis of renewable biomass (glucose, xylitol and sucrose) was reported. Detailed characterizations results indicated that the morphologies and properties of Fe3C@G-CNT composites depended strongly on pyrolysis temperature. Fe3C@G-CNT-700 (prepared at 700 °C) was highly active and stable for the hydrogenation of nitroarenes to anilines at 40 °C, and this catalyst was also active for the selective hydrogenation of CC bond in several compounds. The synthetic strategy, the structure of iron carbide-based composite and the proposed mechanism may open a new avenue for the development of hydrogenation catalysts.
Co-reporter:Juanjuan Shi, Yingyu Wang, Xini Yu, Weichen Du, Zhaoyin Hou
Fuel 2016 Volume 163() pp:74-79
Publication Date(Web):1 January 2016
DOI:10.1016/j.fuel.2015.09.047
•Pt/rGO is active and selective for the production of DMF from HMF under mild conditions.•The yield of DMF reached 73.2% with a 100% conversion of HMF at 120 °C, 3.0 MPa H2.•The preferential adsorption of HMF on Pt/rGO would accelerate its conversion.Reduced graphene oxides supported platinum (Pt/rGO) is extremely active and selective for the production of 2,5-dimethylfuran (DMF) via hydrogenation of 5-hydroxymethylfurfural (HMF) among a series of supported Pt catalysts under mild conditions. The influence of varied reaction parameters, such as solvent, reaction temperature, H2 pressure, and HMF concentration were investigated with respect to the conversion of HMF and the yield of DMF. It was found that the yield of DMF reached 73.2% with a 100% conversion of HMF at 120 °C, 3.0 MPa H2 and 2.0 h.
Co-reporter:Juanjuan Shi, Mengyuan Zhang, Weichen Du, Wensheng Ning and Zhaoyin Hou
Catalysis Science & Technology 2015 vol. 5(Issue 6) pp:3108-3112
Publication Date(Web):22 Apr 2015
DOI:10.1039/C5CY00393H
In this communication, a pyramid shaped alloy-metal oxide–graphene hybrid was synthesized by a facile procedure, in which SnO2 nanoparticles (NPs) (4.8–5.8 nm) were first coated onto the surface of reduced graphene oxide (rGO), and then very fine Pt3Sn NPs (0.6–1.2 nm) were fabricated on the SnO2 NPs on rGO sheets under microwave irradiation in a few minutes. Characterizations disclosed that the SnO2 NPs on rGO were more favorable for the dispersion of Pt, and Pt3Sn formed mainly on the surface of SnO2 NPs. This pyramid shaped Pt3Sn/SnO2/rGO hybrid was highly active, selective and stable for the hydrogenation of the CO bond in unsaturated aldehydes to unsaturated alcohols under mild conditions.
Co-reporter:Jie Fu, Cuiyue Yang, Jianghua Wu, Julia Zhuang, Zhaoyin Hou, Xiuyang Lu
Fuel 2015 Volume 139() pp:678-683
Publication Date(Web):1 January 2015
DOI:10.1016/j.fuel.2014.09.025
•Aviation fuels can be synthesized directly from microalgae lipids in water over Pt/C.•Pt/C is capable for decarboxylation of all test model compounds of microalgae lipids.•Pt/C keeps the catalytic activity on decarboxylation even at the third use.•Mechanism of direct decarboxylation of fatty acid esters is proposed.•Optimum reaction condition for decarboxylation of methyl stearate is obtained.In this contribution, we confirmed that aviation fuels could be synthesized directly from microalgae lipids in water over a Pt/C catalyst without additional hydrogen. After decarboxylation at 330 and 370 °C for 120 min, the oxygen content in the microalgae lipids was significantly reduced and the heating value of produced aviation fuels was greatly increased. The reaction mechanism of direct decarboxylation of microalgae lipids to aviation fuels was further investigated using each of the representative compounds in microalgae lipids, such as methyl laurate, methyl eicosanoate, methyl stearate, ethyl stearate, and tristearin as the starting material in separate reactions under the same conditions. Those reaction conditions, solvent, water loading, catalyst loading and reactant loading, were optimized. It was concluded that among the tested solvents, water was the most favorable for the selective decarboxylation of methyl stearate, that the catalytic decarboxylation rate of fatty acid esters with larger carbon numbers in water was faster than those with smaller carbon numbers, and that the Pt/C catalyst retained its activity through its third use. These results provide new insights for the direct decarboxylation of microalgae lipids to aviation fuels.
Co-reporter:Shuixin Xia, Weichen Du, Liping Zheng, Ping Chen and Zhaoyin Hou
Catalysis Science & Technology 2014 vol. 4(Issue 4) pp:912-916
Publication Date(Web):23 Dec 2013
DOI:10.1039/C3CY00990D
Core–shell structured magnetic Fe2O3@CuMgAl layered double hydroxide (LDH) catalysts were synthesized in a facile route and used in selective hydrogenolysis of glycerol. Characterization disclosed that the thermal stability of the LDH framework, the dispersion of Cu and its activity were enhanced simultaneously in the presence of Fe2O3.
Co-reporter:Shuixin Xia, Liping Zheng, Wensheng Ning, Lina Wang, Ping Chen and Zhaoyin Hou
Journal of Materials Chemistry A 2013 vol. 1(Issue 38) pp:11548-11552
Publication Date(Web):07 Aug 2013
DOI:10.1039/C3TA12819A
Multiwall carbon nanotube (MWCNT)-pillared layered Cu0.4/Mg5.6Al2O8.6 material with doublet meso-pore channels and higher surface area was fabricated and used in hydrogenolysis of glycerol. The activity of surface Cu in MWCNTs–Cu0.4/Mg5.6Al2O8.6 hybrid is higher than those of Pd- and Rh-promoted Cu0.4/Mg5.6Al2O8.6 catalysts.
Co-reporter:Shuixin Xia, Liping Zheng, Lina Wang, Ping Chen and Zhaoyin Hou
RSC Advances 2013 vol. 3(Issue 37) pp:16569-16576
Publication Date(Web):11 Jul 2013
DOI:10.1039/C3RA42543F
Hydrogen-free synthesis of 1,2-propanediol (1,2-PDO) from glycerol was carried out over a series of Cu–Mg–Al catalysts with different (Cu + Mg)/Al ratios. Several hydrogen donors were tested and it was found that ethanol was the best donor for this process, the efficiency of the ethanol donor reached 79.8%. Cu0.4/Mg6.28Al1.32O8.26 showed the best performance among these tested catalysts. The conversion of glycerol and selectivity of 1,2-PDO reached 95.1% and 92.2%, respectively, at 210 °C. Characterizations indicated that the activity of Cu–Mg–Al for this hydrogen-free synthesis of 1,2-PDO depended mainly on the basicity of the catalysts. Both the conversion of glycerol and selectivity to 1,2-PDO could be improved with prolonged time, reaction temperature and the amount of hydrogen donor. The reaction mechanism was proposed.
Co-reporter:Renfeng Nie, Juanjuan Shi, Shuixin Xia, Lian Shen, Ping Chen, Zhaoyin Hou and Feng-Shou Xiao
Journal of Materials Chemistry A 2012 vol. 22(Issue 35) pp:18115-18118
Publication Date(Web):02 Aug 2012
DOI:10.1039/C2JM34652D
Rod-like MnO2 uniformly attached on both side of GO sheets (MnO2/GO) is an efficient heterogeneous catalyst for the synthesis of primary amides from primary alcohols and ammonia as well as from aldehydes or nitriles. Water is the best solvent for these reactions, analytically pure crystals of product could be isolated by simply cooling in ice and this catalyst has excellent recyclability.
Co-reporter:Renfeng Nie, Junhua Wang, Lina Wang, Yu Qin, Ping Chen, Zhaoyin Hou
Carbon 2012 Volume 50(Issue 2) pp:586-596
Publication Date(Web):February 2012
DOI:10.1016/j.carbon.2011.09.017
Reduced graphene oxide (RGO)-supported platinum (Pt) catalyst was prepared by simple ethylene glycol (EG) reduction and used for hydrogenation of nitroarenes. Characterizations showed that EG as a reductant exhibited more advantages than the widely used hydrazine hydrate to fabricate monodispersed, small sized Pt nanoparticles on the surface of RGO. The yield of aniline over the Pt/RGO-EG catalyst reached 70.2 mol-AN/(mol-Pt min) at 0 oC, which is 12.5 and 19.5 times higher than that of multi-walled carbon nanotube- and active carbon-supported Pt catalysts, respectively. When the reaction temperature was increased to 20 oC, the catalytic activity of Pt/RGO-EG jumped to 1138.3 mol-AN/(mol-Pt min), and it was also extremely active for the hydrogenation of a series of nitroarenes. The unique catalytic activity of Pt/RGO-EG is not only related to the well dispersed Pt clusters on the RGO sheets but also the well dispersion of Pt/RGO-EG in the reaction mixture.
Co-reporter:Renfeng Nie, Hong Lei, Saiyong Pan, Lina Wang, Jinhua Fei, Zhaoyin Hou
Fuel 2012 Volume 96() pp:419-425
Publication Date(Web):June 2012
DOI:10.1016/j.fuel.2011.12.048
A series of core–shell structured CuO–ZnO@H-ZSM-5 (CZ@H) catalysts were prepared by homogeneous precipitation through urea hydrolysis. This novel preparation procedure and excellent core–shell structure had contributed to its high-performance for CO hydrogenation under 260 °C, 2.0 MPa and high space velocity (6000 mL/(g-cat h). The space time yield of dimethyl ether (DME) over CZ@H(7.5) reached 0.76 g-DME/g-cat h with a 69.6% selectivity, and these values exceeded that of hybrid catalyst prepared by traditional mixing method (0.37 g-DME/g-cat h, 65.1% selectivity of DME). This high performance of bifunctional CZ@H catalysts could be attributed to the high Cu dispersion and well-defined core–shell structure.Graphical abstractA series of core–shell structured CuO–ZnO@HZSM-5 (CZ@H) catalysts were prepared by homogeneous precipitation through urea hydrolysis. This novel preparation procedure and excellent core–shell structure had contributed to its high-performance for CO hydrogenation under 260 °C, 2.0 MPa and high space velocity (6000 mL/(g-cat h), which strikingly exceeded that of bifunctional catalyst (CZ/H-M) prepared by traditional mixing method.Highlights► Core–shell structured CuO–ZnO@H-ZSM-5 were prepared by homogeneous precipitation. ► The structure of these catalysts were confirmed by XRD, SEM, H2-TPR and N2O titration. ► These catalysts are highly active for CO hydrogenation to DME at high space velocity (>6000 mL/(g-cat h). ► The STY of DME over CZ@H(7.5) reached 0.76 g-DME/g-cat h at 260 °C, 2.0 MPa, H2/CO = 2/1.
Co-reporter:Hong Lei;Ren-feng Nie;Jin-hua Fei
Journal of Zhejiang University-SCIENCE A 2012 Volume 13( Issue 5) pp:395-406
Publication Date(Web):2012 May
DOI:10.1631/jzus.A1100345
The synthesis of methanol and dimethyl ether (DME) from CO hydrogenation has been investigated on Cu-based catalysts. A series of Cu/ZnO/Al2O3 catalysts were prepared using a solvent-free routine which involved a direct blend of copper/zinc/aluminum salts and citric acid, followed by calcination at 450 °C. The calcination processes were monitored using thermogravimetry differential scanning calorimetry (TG-DSC). Catalysts were further characterized using N2 adsorption, scanning electronic microscopy (SEM), X-ray diffraction (XRD), N2O oxidation followed by H2 titration, and temperature-programmed reduction with H2 (H2-TPR). The reduction processes were also monitored with in-situ XRD. The physicochemical properties of catalysts depended strongly on the types of precursor salts, and catalysts prepared using Al acetate and Cu nitrate as starting materials had a larger surface area, larger exposed metallic copper surface area, and lower reduction temperature. The CO hydrogenation performances of these catalysts were compared and discussed in terms of their structures. Catalysts prepared with copper nitrate, zinc and aluminum acetates exhibited the highest catalytic activity.
Co-reporter:Zhenle Yuan, Shuixin Xia, Ping Chen, Zhaoyin Hou, and Xiaoming Zheng
Energy & Fuels 2011 Volume 25(Issue 7) pp:3186-3191
Publication Date(Web):May 25, 2011
DOI:10.1021/ef200366q
Etherification of biodiesel-based glycerol with bioethanol was investigated over a series of catalysts. The etherification of glycerol performed on acid catalysts, such as H-ZSM5, H-β, tungstophosphoric acid (HPW), FeCl3, AlCl3, and H2SO4, was found. Basic catalysts (such as alkaline earth oxides, MgO) are inactive for the reaction. Bulk HPW and SiO2-supported HPW catalysts exhibited the highest activity among the tested catalysts, with a 97.1% conversion of glycerol. Over the HPW catalyst, the etherification reactions were carried out at different temperatures, varied ratios between ethanol and glycerol, different catalyst amounts, and different reaction times. The SiO2-supported HPW catalyst has a high initial activity, but it deactivated gradually because of the leaching of HPW.
Co-reporter:Junhua Wang, Zhenle Yuan, Renfeng Nie, Zhaoyin Hou and Xiaoming Zheng
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 10) pp:4664
Publication Date(Web):April 21, 2010
DOI:10.1021/ie1002069
Nanosized silica gel supported Ni catalysts that have average Ni particle size of 3.7, 11.4, and 11.8 nm were prepared by facile impregnation of different Ni precursors and used for hydrogenation of nitrobenzene (NB). These catalysts were characterized by N2 adsorption, X-ray diffraction, and transmission electron microscopy. It was found that Ni dispersed highly on the surface of silica gel in the catalyst prepared via Ni(en)3(NO3)2, and the detected average Ni particle size was 3.7 nm. On the 3.7 nm sized Ni catalyst, the selectivity of aniline (AN) reached 99% with a 100% conversion of NB in 5.5 h at 90 °C, 1.0 MPa, and NB:Ni = 305 (mole ratio). But, the activities of 11.8 nm sized Ni catalysts and commercial Raney Ni catalyst are quite lower. The reaction network and mechanism of NB hydrogenation on 3.7 nm sized Ni catalyst were discussed on the basis of products distributions at different temperatures and pressures. The calculated activation energy of NB hydrogenation on Ni-5/SiO2-EN catalyst is 54.5 kJ/mol in 70−90 °C.
Co-reporter:Jianzhong Guo, Jing Gao, Binghui Chen, Zhaoyin Hou, Jinhua Fei, Hui Lou, Xiaoming Zheng
International Journal of Hydrogen Energy 2009 Volume 34(Issue 21) pp:8905-8911
Publication Date(Web):November 2009
DOI:10.1016/j.ijhydene.2009.08.084
A series of Ni/SiO2 catalysts containing different amounts of Gd2O3 promoter was prepared, characterized by H2-adsorption and XRD, and used for carbon dioxide reforming of methane (CRM) and methane autothermal reforming with CO2 + O2 (MATR) in a fluidized-bed reactor. The results of pulse surface reactions showed that Ni/SiO2 catalysts containing Gd2O3 promoter could increase the activity for CH4 decomposition, and Raman analysis confirmed that reactive carbon species mainly formed on the Ni/SiO2 catalysts containing Gd2O3 promoter. In this work, it was found that methane activation and reforming reactions proceeded according to different mechanisms after Gd2O3 addition due to the formation of carbonate species. In addition, Ni/SiO2 catalysts containing Gd2O3 promoter demonstrated higher activity and stability in both CRM and MATR reactions in a fluidized bed reactor than Ni/SiO2 catalysts without Gd2O3 even at a higher space velocity.
Co-reporter:Jing Gao, Zhaoyin Hou, Xuesong Liu, Yaowu Zeng, Mengfei Luo, Xiaoming Zheng
International Journal of Hydrogen Energy 2009 Volume 34(Issue 9) pp:3734-3742
Publication Date(Web):May 2009
DOI:10.1016/j.ijhydene.2009.02.074
A series of different amount ZrO2-promoted SiO2 supported Ni catalysts were prepared and used for methane autothermal reforming with CO2 and O2 [MATR] to synthesis gas in a fluidized bed reactor. Pulse-injected surface reactions and in situ XRD characterizations disclosed that CO2 dissociated exclusively at the boundary between Ni and ZrO2. O species derived from CO2 dissociation overflowed to metallic Ni and accelerated the activation of methane. Ni/5ZrO2–SiO2 catalyst with larger Ni–ZrO2 boundary exhibited the best activity and stability for MATR even at an extremely space velocity 90,000 h−1.
Co-reporter:Jing Gao, Jianzhong Guo, Dan Liang, Zhaoyin Hou, Jinhua Fei, Xiaoming Zheng
International Journal of Hydrogen Energy 2008 Volume 33(Issue 20) pp:5493-5500
Publication Date(Web):October 2008
DOI:10.1016/j.ijhydene.2008.07.040
Production of syngas via autothermal reforming of methane (MATR) in a fluidized bed reactor was investigated over a series of combined CeO2–ZrO2/SiO2 supported Ni catalysts. These combined CeO2–ZrO2/SiO2 supports and supported Ni catalysts were characterized by nitrogen adsorption, XRD, NH3-TPD, CO2-TPD and H2-TPR. It was found that the combined supports integrated the advantages of SiO2 and CeO2, ZrO2. That is, they have bigger surface area (about 300 m2/g) than pure CeO2 and ZrO2, stronger acidity and alkalescence than that of pure SiO2, and enhanced the mobility of H adatoms. Ni species dispersed highly on these combined CeO2–ZrO2/SiO2 supports, and became more reducible. Ni catalysts on the combined supports possess higher CO2 adsorption ability, higher methane activation ability and exhibited higher activity for MATR. H2/CO ratio in product gas could be controlled successfully in the range of 0.99–2.21 by manipulating the relative concentrations of CO2 and O2 in feed.
Co-reporter:Jianzhong Guo, Zhaoyin Hou, Jing Gao and Xiaoming Zheng
Energy & Fuels 2008 Volume 22(Issue 3) pp:1444
Publication Date(Web):April 5, 2008
DOI:10.1021/ef7003865
The partial oxidation and CO2 reforming of coke oven gas (COG) to syngas was investigated on differently sized Ni catalysts in a fluidized-bed reactor. It was found that the catalytic performance of Ni depends strongly on its particle size. The small-sized Ni catalyst exhibited higher activity and higher selectivity in the partial oxidation of COG. The conversion of CH4 was kept at 80.7% at a lower temperature (750 °C) and a wide space velocity (from 8000 to 80 000 h−1). CO2 reforming of COG is also an efficient route for syngas production. The H2/CO ratio in the COG-derived syngas could be controlled by manipulating the concentration of O2 or CO2 added in the feed. The yield of produced syngas increases with an increase in temperature.
Co-reporter:Zhaoyin Hou, Ping Chen, Heliang Fang, Xiaoming Zheng, Tatsuaki Yashima
International Journal of Hydrogen Energy 2006 Volume 31(Issue 5) pp:555-561
Publication Date(Web):April 2006
DOI:10.1016/j.ijhydene.2005.06.010
Several supported metal (Ru, Rh, Pt, Pd, Ir, Ni, Co) catalysts were prepared and used for methane reforming with CO22. Nobel metals (5 wt%, loading amount) showed higher coke resistance ability, while their activity was lower than that of Ni and Co (10 wt%, loading amount). Pulse CO adsorption experiments indicated that the dispersion of noble metals (such as Rh) depended strongly on its loading amount and the surface area of the support. Rh dispersed highly on meso-porous Al22O33 (with high surface area) and exhibited higher coke resistance ability and higher reforming activity. At the same time, small amount of Rh enhanced obviously both the reforming activity and coke resistance ability of Ni.
Co-reporter:Zhao-Yin Hou;Jin-Hua Fei;Jing Gao;Hui Lou;Xiao-Ming Zheng;Kai Shen
Chinese Journal of Chemistry 2006 Volume 24(Issue 6) pp:721-723
Publication Date(Web):7 JUN 2006
DOI:10.1002/cjoc.200690137
Highly dispersed Ni catalysts on spherical SiO2 were prepared by simple impregnation of Ni(acac)2, [Ni-(NH3)6−n(H2O)n]2+, [Ni(en)3]2+ and [Ni(EDTA)]2−. Pulse adsorption of H2 and TEM analysis results confirmed that Ni was dispersed very well on the surface of SiO2 even after calcination (4 h) and reduction (1 h) at high temperature of 800 °C. These highly dispersed and uniquely sized Ni crystallites were more stable and more reactive for both autothermal reforming and partial oxidation of methane in fluidized reactor.
Co-reporter:Chen Ping;Hou Zhao-Yin;Zheng Xiao-Ming
Chinese Journal of Chemistry 2005 Volume 23(Issue 7) pp:
Publication Date(Web):16 AUG 2005
DOI:10.1002/cjoc.200590847
Ni/SiO2 catalysts promoted by alkali metals K and Cs or alkaline earth metals Mg, Ca, Sr and Ba were prepared, characterized by H2-TPR and XRD, and used for the production of synthesis gas via methane reforming with CO2. Though K and Cs promoted Ni catalysts could eliminate coke deposition, the reforming activity of these promoted catalysts was decreased heavily. Mg and Ca promoted Ni/SiO2 catalysts exhibited excellent coke resistance ability with minor loss of the reforming activity of Ni/SiO2. Ba showed poor coke resistance ability and small amount of Sr increased the formation of coke. The possible mechanism of these promoters was discussed.
Co-reporter:Zhaoyin Hou, Osamu Yokota, Takumi Tanaka, Tatsuaki Yashima
Applied Surface Science 2004 Volume 233(1–4) pp:58-68
Publication Date(Web):30 June 2004
DOI:10.1016/j.apsusc.2004.03.223
Abstract
Small amounts Sn doped Ni catalysts exhibited excellent coke resistance ability with minor loss of reforming activity in CH4 reforming with CO2. Temperature-programmed reduction with H2 (H2-TPR) showed that the addition of Sn increased the reducibility of Ni. X-ray photoelectron spectroscopy (XPS) analysis of Ni/α-Al2O3 (I), Sn0.02Ni/α-Al2O3 (II), indicated that the binding energy of the Ni 2p level was decreased from 855.7 (I) to 855.2 eV (II) by the addition of Sn. Field emission scanning electron microscopy (FE-SEM) and field emission transmission electron microscopy (FE-TEM) analysis of the fresh and used catalysts (I, II) revealed that the added Sn increased the dispersion of Ni and retarded sintering of Ni. XPS and EDX also disclosed that Sn was aggregated on the surface of Ni, and the coverage of Sn on the surface of Ni depressed the reforming activity.
Co-reporter:Liping Zheng, Shuixin Xia, Zhaoyin Hou
Applied Clay Science (December 2015) Volume 118() pp:68-73
Publication Date(Web):December 2015
DOI:10.1016/j.clay.2015.09.002
Co-reporter:Shuixin Xia, Renfeng Nie, Xiuyang Lu, Lina Wang, Ping Chen, Zhaoyin Hou
Journal of Catalysis (December 2012) Volume 296() pp:1-11
Publication Date(Web):1 December 2012
DOI:10.1016/j.jcat.2012.08.007
A series of Cu0.4/Zn5.6−xMgxAl2O8.6 catalysts with different Zn/Mg ratios were prepared and used in hydrogenolysis of glycerol in aqueous solution. This reaction proceeded more easily and efficiently over Cu0.4/Zn0.6Mg5.0Al2O8.6 than Cu0.4/Mg5.6Al2O8.6 and Cu0.4/Zn5.6Al2O8.6. The selectivity of 1,2-propanediol is higher than 98.6% in all experiments over Cu0.4/Zn0.6Mg5.0Al2O8.6, and the activity of surface Cu atoms reached 26.6 h−1 at 200 °C. The structure, morphology, acidity (basicity), and adsorption ability of glycerol/hydrogen for these catalysts were characterized and discussed. It was concluded that the conversion of glycerol depended strongly on the basicity of these Cu-based catalysts and hydrogen spillover also enhanced its performance.Graphical abstractGlycerol hydrogenolysis activity over Cu/Zn–Mg–Al–O catalysts depended strongly on its basicity and hydrogen spillover also enhanced its performance. The calculated TOF of surface Cu atom in Cu0.4/Zn0.6Mg5.0Al2O8.6 reached 26.6 h−1 at 200 °C in aqueous solution.Download high-res image (105KB)Download full-size imageHighlights► The acidity/basicity of Cu/Zn–Mg–Al–O catalysts could be manipulated via adjusting Zn/Mg ratio. ► The conversion of glycerol depended strongly on the basicity of Cu/Zn–Mg–Al–O. ► Hydrogen spillover from Cu to ZnO also enhanced its catalytic performance. ► Cu0.4/Zn0.6Mg5.0Al2O8.6 exhibited the best performance for hydrogenolysis of glycerol at 180 °C. ► The TOF of surface Cu atom in Cu0.4/Zn0.6Mg5.0Al2O8.6 reached 26.6 h−1 at 200 °C.
Co-reporter:Weichen Du, Liping Zheng, Xuewen Li, Jie Fu, Xiuyang Lu, Zhaoyin Hou
Applied Clay Science (April 2016) Volume 123() pp:166-172
Publication Date(Web):April 2016
DOI:10.1016/j.clay.2016.01.032
Co-reporter:Mengyuan Zhang, Juanjuan Shi, Yanyan Sun, Wensheng Ning, Zhaoyin Hou
Catalysis Communications (5 October 2015) Volume 70() pp:72-76
Publication Date(Web):5 October 2015
DOI:10.1016/j.catcom.2015.08.002
•N-doped MWCNT supported Pt NPs (1.8 nm) was prepared in a facile routine.•N-MWCNTs can improve the dispersion of Pt through SMSI and electron donating.•Pt/N-MWCNT is active and stable for the selective oxidation of glycerol.•Deactivation of Pt during glycerol oxidation can be depressed by the addition of nitrogen.In this communication, N-doped multiwall carbon nanotube (N-MWCNT) supported Pt NPs (1.8 nm) were prepared via a facile routine under microwave irradiation and tested in the selective oxidation of glycerol in an aqueous base-free solution. Characterizations confirmed that N-MWCNTs could improve the dispersion of Pt through strengthened metal-support interactions and donate its electron to metallic Pt. This electron-enriched Pt NPs on the surface of N-MWCNTs is active and stable for the selective oxidation of glycerol.N-doped MWCNT supported Pt NPs is highly active, selective and stable for the oxidation of glycerol in an aqueous base-free solution.Download high-res image (153KB)Download full-size image
Co-reporter:Renfeng Nie, Juanjuan Shi, Weichen Du, Zhaoyin Hou
Applied Catalysis A: General (5 March 2014) Volume 473() pp:1-6
Publication Date(Web):5 March 2014
DOI:10.1016/j.apcata.2013.12.029
Co-reporter:Dingfeng Jin, Zhaoyin Hou, Liwei Zhang, Xiaoming Zheng
Catalysis Today (29 February 2008) Volume 131(Issues 1–4) pp:378-384
Publication Date(Web):29 February 2008
DOI:10.1016/j.cattod.2007.10.049
Selective synthesis of para–para′-dimethyldiphenylmethane (para–para′-DMDPM) from the condensation between toluene and formaldehyde was investigated over H-X, H-Y, H-ZSM-5, H-mordenite and MCM-41. Characterizations (NH3-TPD-MS and pore structure) disclosed that the catalytic activity of various zeolites depends mainly on its strong acid site and accessibility of the internal pores. H-beta zeolite, with a unique pore sized in 0.66 nm and higher proportion of stronger acid site, exhibited the highest activity and stereo-selectivity (86.5%). Small sized H-beta zeolite was more active due to the enhanced accessibility of its acid site, and this kind of zeolite remained a higher stereo-selectivity (>80%) even at higher temperature, longer reaction time and recycle usage. The best yield of para–para′-DMDPM reached 71.1% at 140°C over H-beta zeolite and it could be used in recycle without loss of its structure, activity and stereo-selectivity.
Co-reporter:Jing Gao, Zhaoyin Hou, Jianzhong Guo, Yinghong Zhu, Xiaoming Zheng
Catalysis Today (29 February 2008) Volume 131(Issues 1–4) pp:278-284
Publication Date(Web):29 February 2008
DOI:10.1016/j.cattod.2007.10.019
In this contribution, a commercial spherical SiO2 was modified with different amounts of La2O3, and used as the support of Ni catalysts for autothermal reforming of methane in a fluidized-bed reactor. Nitrogen adsorption, XRD and H2-TPR analysis indicated that La2O3-modified SiO2 had higher surface area, strengthened interaction between Ni and support, and improved dispersion of Ni. CO2-TPD found that La2O3 increased the alkalescence of SiO2 and improved the activation of CO2. Coking reaction (via both temperature-programmed surface reaction of CH4 (CH4-TPSR) and pulse decomposition of CH4) disclosed that La2O3 reduced the dehydrogenation ability of Ni. CO2-TPO, O2-TPO (followed after CH4-TPSR) confirmed that only part amount of carbon species derived from methane decomposition could be removed by CO2, and O2 in feed played a crucial role for the gasification of the inactive surface carbons. Ni/xLa2O3-SiO2 (x = 10, 15, 30) possessed high activity and excellent stability for autothermal reforming of methane in a fluidized-bed reactor.
Co-reporter:Shuixin Xia, Zhenle Yuan, Lina Wang, Ping Chen, Zhaoyin Hou
Applied Catalysis A: General (22 August 2011) Volume 403(Issues 1–2) pp:173-182
Publication Date(Web):22 August 2011
DOI:10.1016/j.apcata.2011.06.026
Co-reporter:Dingfeng Jin, Jing Gao, Zhaoyin Hou, Yan Guo, Xiuyang Lu, Yinghong Zhu, Xiaoming Zheng
Applied Catalysis A: General (15 January 2009) Volume 352(Issues 1–2) pp:
Publication Date(Web):15 January 2009
DOI:10.1016/j.apcata.2008.10.020
Under microwave irradiation, 12-tungstophosphoric acid (HPW) could be successfully synthesized in situ and encapsulated in the supercage of ultra stable Y (USY) in several minutes. But the framework of USY collapsed easily in traditional hydrothermal synthesis routine. 31P MAS NMR, transmission electron microscopy (HR-TEM), N2 adsorption, inductively coupled plasma (ICP) and X-ray diffraction (XRD) characterizations found that the formed HPW molecule located separately in the supercage of USY. Temperature-programmed desorption of NH3 (NH3-TPD) showed that HPW-USY exhibited stronger acidity than that of pure USY, and adsorbed pyridine infrared (Py-IR) disclosed that the concentration of Brönsted acid sites was enhanced. This hybrid solid acid exhibited higher activity in the synthesis of 4,4′-dimethyldiphenylmethane via toluene and formaldehyde and could be utilized as a solid acid catalyst in aqueous solutions.Download full-size image
Co-reporter:Zhaoyin Hou, Jing Gao, Jianzhong Guo, Dan Liang, Hui Lou, Xiaoming Zheng
Journal of Catalysis (10 September 2007) Volume 250(Issue 2) pp:331-341
Publication Date(Web):10 September 2007
DOI:10.1016/j.jcat.2007.06.023
A series of different-sized Ni catalysts (4.5–45.0 nm) were prepared and used for methane autothermal reforming with CO2 and O2 in a fluidized-bed reactor. It was found that the activity and stability of Ni catalysts depend strongly on the particle size and the operating space velocity. Small sized Ni is more active and stable at space velocity <54,000 h−1. Characterizations disclosed that methane decomposition rate decreases with the enlarging Ni particle size, and some of the surface carbons (derived from methane decomposition) are inactive in CO2 atmosphere. As the methane decomposition rate slows on larger Ni particles and at higher space velocity to ensure complete conversion of the oxygen, surface Ni will be gradually oxidized by remaining O2, leading to Ni deactivation.
Co-reporter:Dan Liang, Jing Gao, Junhua Wang, Ping Chen, Yanfei Wei, Zhaoyin Hou
Catalysis Communications (1 July 2011) Volume 12(Issue 12) pp:1059-1062
Publication Date(Web):1 July 2011
DOI:10.1016/j.catcom.2011.03.019
A series of carbon supported bimetallic Pt―Cu catalysts were prepared and used for glycerol oxidation with oxygen in a base-free aqueous solution. It was found that bimetallic Pt―Cu/C was more active than monometallic Pt/C towards selective oxidation of glycerol to glyceric acid. The selectivity of free glyceric acid reached 70.8% at an 86.2% conversion of glycerol over 5Pt―Cu/C. Highly dispersed bimetallic Pt―Cu nanoparticles with small particle size in dominant alloyed phase of PtCu3 were confirmed by XRD and TEM in the bimetallic Pt―Cu/C catalyst, which is proposed to contribute to the improved performance.Download full-size imageResearch highlights► Selective oxidation of glycerol was performed on Pt―Cu/C in base-free conditions. ► All Cu modified Pt/C catalysts exhibited higher activity than the corresponding parent Pt/C. ► 3Pt–Cu/C (3 wt.%) exhibited higher activity than 5Pt/C (5 wt.%). ► Highly dispersed PtCu3 alloy was proposed to contribute to the improved performance.
Co-reporter:Renfeng Nie, Juanjuan Shi, Shuixin Xia, Lian Shen, Ping Chen, Zhaoyin Hou and Feng-Shou Xiao
Journal of Materials Chemistry A 2012 - vol. 22(Issue 35) pp:NaN18118-18118
Publication Date(Web):2012/08/02
DOI:10.1039/C2JM34652D
Rod-like MnO2 uniformly attached on both side of GO sheets (MnO2/GO) is an efficient heterogeneous catalyst for the synthesis of primary amides from primary alcohols and ammonia as well as from aldehydes or nitriles. Water is the best solvent for these reactions, analytically pure crystals of product could be isolated by simply cooling in ice and this catalyst has excellent recyclability.
Co-reporter:Shuixin Xia, Liping Zheng, Wensheng Ning, Lina Wang, Ping Chen and Zhaoyin Hou
Journal of Materials Chemistry A 2013 - vol. 1(Issue 38) pp:NaN11552-11552
Publication Date(Web):2013/08/07
DOI:10.1039/C3TA12819A
Multiwall carbon nanotube (MWCNT)-pillared layered Cu0.4/Mg5.6Al2O8.6 material with doublet meso-pore channels and higher surface area was fabricated and used in hydrogenolysis of glycerol. The activity of surface Cu in MWCNTs–Cu0.4/Mg5.6Al2O8.6 hybrid is higher than those of Pd- and Rh-promoted Cu0.4/Mg5.6Al2O8.6 catalysts.
Co-reporter:Juanjuan Shi, Mengyuan Zhang, Weichen Du, Wensheng Ning and Zhaoyin Hou
Catalysis Science & Technology (2011-Present) 2015 - vol. 5(Issue 6) pp:NaN3112-3112
Publication Date(Web):2015/04/22
DOI:10.1039/C5CY00393H
In this communication, a pyramid shaped alloy-metal oxide–graphene hybrid was synthesized by a facile procedure, in which SnO2 nanoparticles (NPs) (4.8–5.8 nm) were first coated onto the surface of reduced graphene oxide (rGO), and then very fine Pt3Sn NPs (0.6–1.2 nm) were fabricated on the SnO2 NPs on rGO sheets under microwave irradiation in a few minutes. Characterizations disclosed that the SnO2 NPs on rGO were more favorable for the dispersion of Pt, and Pt3Sn formed mainly on the surface of SnO2 NPs. This pyramid shaped Pt3Sn/SnO2/rGO hybrid was highly active, selective and stable for the hydrogenation of the CO bond in unsaturated aldehydes to unsaturated alcohols under mild conditions.
Co-reporter:Juanjuan Shi, Mengsi Zhao, Yingyu Wang, Jie Fu, Xiuyang Lu and Zhaoyin Hou
Journal of Materials Chemistry A 2016 - vol. 4(Issue 16) pp:NaN5848-5848
Publication Date(Web):2016/03/22
DOI:10.1039/C6TA01317A
Fast pyrolysis of biomass for bio-oil production is a direct route to renewable liquid fuels, but raw bio-oil must be upgraded in order to remove easily polymerized compounds (such as phenols and furfurals). Herein, a synthesis strategy for graphene encapsulated Ru nanoparticles (NPs) on carbon sheets (denoted as Ru@G-CS) and their excellent performance for the upgrading of raw bio-oil were reported. Ru@G-CS composites were prepared via the direct pyrolysis of mixed glucose, melamine and RuCl3 at varied temperatures (500–800 °C). Characterization indicated that very fine Ru NPs (2.5 ± 1.0 nm) that were encapsulated within 1–2 layered N-doped graphene were fabricated on N-doped carbon sheets (CS) in Ru@G-CS-700 (pyrolysis at 700 °C). And the Ru@G-CS-700 composite was highly active and stable for hydrogenation of unstable components in bio-oil (31 samples including phenols, furfurals and aromatics) even in aqueous media under mild conditions. This work provides a new protocol to the utilization of biomass, especially for the upgrading of bio-oil.
Co-reporter:Shuixin Xia, Weichen Du, Liping Zheng, Ping Chen and Zhaoyin Hou
Catalysis Science & Technology (2011-Present) 2014 - vol. 4(Issue 4) pp:NaN916-916
Publication Date(Web):2013/12/23
DOI:10.1039/C3CY00990D
Core–shell structured magnetic Fe2O3@CuMgAl layered double hydroxide (LDH) catalysts were synthesized in a facile route and used in selective hydrogenolysis of glycerol. Characterization disclosed that the thermal stability of the LDH framework, the dispersion of Cu and its activity were enhanced simultaneously in the presence of Fe2O3.
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