Cu-Co合成低碳醇催化剂的性能

INVESTIGATION ON PERFORMANCE OF Cu-Co CATALYST FOR HIGHER ALCOHOL SYNTHESIS FROM SYNGAS

用不同的沉淀方法制备了Cu-Co催化剂,用XRD,XPS,TPR和BET技术对催化剂前体以及催化剂的物相等进行了表征,用固定床反应器考察了催化剂的合成低碳醇活性。结果表明:用并流共沉淀法制备催化剂时,催化剂是由细小的CuO晶粒和Co3O4晶粒以紧密排列的形式均匀分散在颗粒中,CuO和Co3O4间的相互作用大于用其他方法制备的催化剂。同时,用并流法制备的催化剂的低碳醇合成活性以及醇选择性都好于用其他方法制备的催化剂。用分步沉淀法制备催化剂时,催化剂的二次粒子是由内部富CuO和外层富Co3O4的颗粒组成。由此制备的催化剂具有较小的比表面积,催化活性和醇选择性较低,而有利于烃的生成和CO水煤气变换反应。

The Cu-Co catalysts have been made by different co-current precipitation method and the influence of addition method on the precursors and catalysts were investigated using XRD,XPS,TPR and BET methods.The catalytic activity of the catalysts for higher alcohols synthesis was evaluated in a pressurized fixed-bed reactor.It was found that when the sample was prepared by co-current precipitation method,the catalyst particle was composed of fine CuO grain and Co3O4 grain homogeneously arranged in the form of compact accumulation and very well dispersed.The mutual interaction between CuO and Co3O4 was stronger than the other samples.At the same time,the catalyst has the highest activity and higher alcohol selectivity.When the sample was made by separate precipitation method,the catalyst was composed of particle whose core was rich in CuO while the outer surface was rich in Co3 O4 and has lower surface area and lower catalytic activity as well as lower alcohol selectivity,favorable to the formation of hydrocarbon and WGS reaction.