凝胶网格共沉淀法制备CuO/ZnO/Al_2O_3及其催化CO_2加氢合成甲醇研究

以琼脂为分散介质采用凝胶网格沉淀法制备了CuO/ZnO/Al2O3催化剂,利用N2吸附-脱附、XRD、H2-TPR、TEM等方法对催化剂进行了表征,研究了其CO2加氢合成甲醇的催化反应性能,并与草酸盐凝胶共沉淀法和传统并流共沉淀法制备的催化剂进行了对比。结果表明:采用凝胶网格共沉淀法制备的催化剂具有较小的颗粒尺寸和较低的还原温度,在2.0MPa、230℃、空速2400mL/(g.h)、V(H2)∶V(CO2)=3∶1的反应条件下进行CO2加氢合成甲醇反应,甲醇的选择性和收率分别为43.12%和6.63%,相对其它两种方法制备的催化剂有比较明显的提高。

Preparation of CuO/ZnO/Al_2O_3 catalyst by gel-network-coprecipitation and its catalytic performance for CO_2 hydrogenation to methanol

A CuO/ZnO/Al2O3 catalyst was prepared by gel-network-coprecipitation with agar as the dispersion medium and characterized by N2 adsorption-desorption,XRD,TPR and TEM.The catalytic performance of the catalyst for CO2 hydrogenation to methanol was evaluated and compared with two catalysts prepared by oxalate gel-coprecipitation and conventional coprecipitation,respectively.The results indicated that compared to the catalysts prepared by the other two methods,the catalyst prepared by gelnetwork-coprecipitation had smaller particle size and lower reduction temperature,and improved obviously the selectivity and yield in the reaction of CO2 hydrogenation to methanol,which were 43.12% and 6.63%,respectively,under the reaction conditions of 2.0MPa,230℃,H2/CO2volume ratio of 3∶1 and GHSV of 2400mL·g-1·h-1.