Methanol synthesis from hydrogenation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M（Cu,Zn）-ammonia complexes （DMAC） at various temperatures.The catalysts were characterized in d...Methanol synthesis from hydrogenation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M（Cu,Zn）-ammonia complexes （DMAC） at various temperatures.The catalysts were characterized in detail,including X-ray diffraction,N2 adsorption-desorption,N2O chemisorption,temperature-programmed reduction and evolved gas analyses.The influences of DMAC temperature,reaction temperature and specific Cu surface area on catalytic performance are investigated.It is considered that the aurichalcite phase in the precursor plays a key role in improving the physiochemical properties and activities of the final catalysts.The catalyst from rich-aurichalcite precursor exhibits large specific Cu surface area and high space time yield of methanol （212 g/（Lcat·h）;T=513 K,p=3MPa,SV=12000 h-1）.展开更多
Methanol steam reforming(MSR) is an attractive approach to produce hydrogen for fuel cells.Due to the limited catalyst loading volume and frequent start-ups and shut-downs on board,it is highly desired to develop an e...Methanol steam reforming(MSR) is an attractive approach to produce hydrogen for fuel cells.Due to the limited catalyst loading volume and frequent start-ups and shut-downs on board,it is highly desired to develop an extremely active and robust catalyst.Herein,on the basis of industrial Cu/ZnO/Al_(2) O_(3) catalysts,a series of CuZnAl-xMg catalysts with enhanced Cu-ZnO synergy were synthesized via magnesium assisted strategy.The incorporation of magnesium was found to be beneficial to the enhancement of catalytic activity and stability of catalyst.A combination of complementa ry characterizations(e.g.XRD,H_(2)-TPR,N_(2) O chemisorption,TEM,XPS analysis etc.) proves that isomorphous substitution of Cu^(2+)in malachite phase gives rise to more dispersive Cu and ZnO NPs,and the increased Cu^(+)/Cu~0 ratio indicates the strengthened Cu-ZnO synergy effect,which leads to the boosted stability during the thermal treatment.展开更多
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...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.展开更多
基金supported by the National Basic Research Program of China (No. 2011CB201404)the financial support of the State Key Laboratory for Oxo Synthesis and Selective Oxidation (OSSO) of China
文摘Methanol synthesis from hydrogenation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M（Cu,Zn）-ammonia complexes （DMAC） at various temperatures.The catalysts were characterized in detail,including X-ray diffraction,N2 adsorption-desorption,N2O chemisorption,temperature-programmed reduction and evolved gas analyses.The influences of DMAC temperature,reaction temperature and specific Cu surface area on catalytic performance are investigated.It is considered that the aurichalcite phase in the precursor plays a key role in improving the physiochemical properties and activities of the final catalysts.The catalyst from rich-aurichalcite precursor exhibits large specific Cu surface area and high space time yield of methanol （212 g/（Lcat·h）;T=513 K,p=3MPa,SV=12000 h-1）.
基金Natural Science Foundation of Zhejiang Province (LQ21B060007)。
文摘Methanol steam reforming(MSR) is an attractive approach to produce hydrogen for fuel cells.Due to the limited catalyst loading volume and frequent start-ups and shut-downs on board,it is highly desired to develop an extremely active and robust catalyst.Herein,on the basis of industrial Cu/ZnO/Al_(2) O_(3) catalysts,a series of CuZnAl-xMg catalysts with enhanced Cu-ZnO synergy were synthesized via magnesium assisted strategy.The incorporation of magnesium was found to be beneficial to the enhancement of catalytic activity and stability of catalyst.A combination of complementa ry characterizations(e.g.XRD,H_(2)-TPR,N_(2) O chemisorption,TEM,XPS analysis etc.) proves that isomorphous substitution of Cu^(2+)in malachite phase gives rise to more dispersive Cu and ZnO NPs,and the increased Cu^(+)/Cu~0 ratio indicates the strengthened Cu-ZnO synergy effect,which leads to the boosted stability during the thermal treatment.
基金supported by the National Natural Science Foundation of China (Nos. 21073159 and 90610002)the National Basic Research Program (973) of China (No. 2007CB210207)the Zhejiang Provincial Natural Science Foundation of China (No. Z406142)
文摘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.
