制备低碳醇的CuZnX催化剂的结构与性能研究

Structure and properties of CuZnX catalysts for the synthesis of higher alcohols

采用溶胶凝胶法制备CuZnX(X=Al、Mg、Si和Ti)催化剂前驱体,773K焙烧后制得的催化剂用于一氧化碳加氢制取低碳醇的反应。通过XRD、H2-TPR、BET、CO2-TPD-MS手段对催化剂进行表征,考察CuZnX催化剂结构对其合成低碳醇性能的影响。结果发现:CuZnX催化剂中不同的第三组分会影响催化剂的晶型和比表面积,同时改变Cu物种的形态和碱性位的分布,进而影响催化剂的活性;催化剂具有较完整的晶型、不同形态Cu物种的协同作用以及适宜比例的弱碱中心和中强碱中心皆有利于低碳醇的生成。

CuZnX(X=Al, Mg, Si and Ti) catalyst precursors were prepared by sol-gel method. The catalysts obtained by calcining the precursors at 773K were characterized by XRD and H2-TPR,BET and CO2-TPD-MS to investigate the effect of catalyst structure on CO hydrogenation to prepare higher alcohols. The results show that the third component X in the CuZnX catalysts has a significant effect on the crystal form, specific surface area, Cu species form and basic sites distribution of the catalysts, which can affect the activity of the catalysts. The catalyst has a relatively complete crystal form, synergistic effect of different forms of Cu species, and a appropriate ratio of weak base sites to medium-strong base sites are favorable for the formation of lower alcohols.