用于CO_2加氢反应的超细CuO－ZnO－SiO_2催化剂的制备研究

采用醇盐法制备了超细ＣｕＯ－ＺｎＯ－ＳｉＯ２催化剂，进行了ＣＯ２加氢反应和透射电镜测试，同时以超细ＣｕＯ－ＳｉＯ２为对比，分别进行了ＸＲＤ、ＴＰＲ研究。对于ＣＯ２加氢反应，ＣｕＯ－ＳｉＯ２催化剂在加入ＺｎＯ组份后催化活性显著提高。ＴＥＭ测试表明ＣｕＯ－ＺｎＯ－ＳｉＯ２催化剂前体在４００℃及６００℃焙烧后平均粒径分别为２８ｎｍ和３４ｎｍ。ＸＲＤ测试表明在ＣｕＯ－ＳｉＯ２体系中存在ＣｕＯ晶相，但更接近于无定形或微晶状态；而在ＣｕＯ－ＺｎＯ－ＳｉＯ２体系中，则存在ＣｕＯ晶相和ＺｎＯ晶相。ＴＰＲ研究表明，ＣｕＯ与ＺｎＯ之间存在相互作用，随ＺｎＯ含量增加，ＣｕＯ还原峰向高温移动。ＺｎＯ对ＣｕＯ还原最大峰温的影响取决于ＺｎＯ加入相对量的变化，即ＺｎＯ／ＣｕＯ（ｍａｓｓ％）比值。

Preparation and investigation of ultrafine CuO-ZnO-SIO_2 catalyst for CO_2 hydrogenation

An ultrafine CuO-ZnO-SiO2 catalyst for CO2 hydrogenation was prepared by alkoxide method, of which a comparative investigation with the ultrafine CuO-SiO2 was carried out by TEM (Transmission Electron Micrography),XRD (x-Ray Diffraction) and TPR (Temperature-Programmed Reduction ). The main products of CO2 hydrogenation over the CuO-ZnO-SiO2 catalyst were methanol and CO.TEM determination indicated that the average particle diameters of the precursor of the CuO-ZnO-SiO2 catalyst, calcined at 400 and 600℃,were 28nm and 34nm respectively. In the CuO-SiO2 system, CuO showed crystalline pattern, but more like amorphorious or microcrystallite. However, in the CuO-ZnO-SiO2system, both CuO and ZnO exhibited crystalline patterns. With the addition of ZnO to the CuO-SiO2 system, there existed interactions between them, leading to an increase of CuO reduction temperature.