Dimethyl ether synthesis from CO_2 hydrogenation on La-modified CuO-ZnO-Al_2O_3 /HZSM-5 bifunctional catalysts  

作　　者：高文桂 王华 王禹皓 郭伟 贾淼尧 

机构地区：[1]Faculty of Metallurgy and Energy Engineering,Kunming University of Science and Technology [2]Engineering Research Center ofMetallurgical Energy Conservation and Emission Reduction,Ministry of Education,Kunming University of Science and Technology [3]State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Cleaning Utilization in Yunnan Province,Kunming University of Science andTechnology

出　　处：《Journal of Rare Earths》2013年第5期470-476,共7页稀土学报（英文版）

基　　金：supported by the National Key Technologies R&D Program of China(2011BAC01B03);the Natural Science Foundation of Yunnan Province(2013FZ035);support by Kunming University of Science and Technology through the Fund for Testingand Analyzing(No.2010213)

摘　　要：A series of CuO-ZnO-Al2O3-La2O3/HZSM-5 biftmctional catalysts with various La loadings for dimethyl ether （DME） directly synthesized from CO2 hydrogenation were prepared. The catalysts were characterized with N2 adsorption-desorption, X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, NH3 temperature-programmed desorption （NH3-TPD） and N2O titration techniques, and tested for the synthesis of DME directly from CO2 hydrogenation in a fixed-bed reactor. The results showed that the reducibility, dispersion ofbifunctional catalysts were strongly dependent on the addition of La. With the addition of appropri- ate amount of La, the crystaUite size of CuO was decreased and the dispersion of Cu on the surface was enhanced, which resulted in the increased conversion of CO2. It was also found that the selectivity to DME was related to the intensity and amount of strong acid site on the catalyst surface. The presence of La favored the production of DME, and the optimum catalytic activity was obtained when the amount of La was 2.0 wt.%.A series of CuO-ZnO-Al2O3-La2O3/HZSM-5 biftmctional catalysts with various La loadings for dimethyl ether （DME） directly synthesized from CO2 hydrogenation were prepared. The catalysts were characterized with N2 adsorption-desorption, X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, NH3 temperature-programmed desorption （NH3-TPD） and N2O titration techniques, and tested for the synthesis of DME directly from CO2 hydrogenation in a fixed-bed reactor. The results showed that the reducibility, dispersion ofbifunctional catalysts were strongly dependent on the addition of La. With the addition of appropri- ate amount of La, the crystaUite size of CuO was decreased and the dispersion of Cu on the surface was enhanced, which resulted in the increased conversion of CO2. It was also found that the selectivity to DME was related to the intensity and amount of strong acid site on the catalyst surface. The presence of La favored the production of DME, and the optimum catalytic activity was obtained when the amount of La was 2.0 wt.%.

关 键 词：CO2 hydrogenation DME bifunctional catalyst LANTHANUM rare earths 

分 类 号：O623.423[理学—有机化学]