Dimethyl ether synthesis from CO2 hydrogenation on La-modified CuO-ZnO-Al2O3/HZSM-5 bifunctional catalysts

• Published in: Journal of rare earths 2013-05, Vol.31 (5), p.470-476
• Main Author: 高文桂 王华 王禹皓 郭伟 贾淼尧
• Format: Article
• Language: English
• Subjects: ALUMINUM OXIDE; bifunctional catalyst; CARBON DIOXIDE; Catalysis; CATALYSTS; CO2 hydrogenation; CO2加氢; COPPER OXIDE; Dimethyl ether; Dispersions; DME; FABRICATION; HYDROGEN; Hydrogenation; lanthanum; NH3-TPD; Rare earth metals; rare earths; Synthesis; ZINC OXIDE; 二甲醚; 催化剂表面; 加氢合成; 双功能催化剂; 程序升温脱附; 香格里拉
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(12)60305-6

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.%.