钾助剂对CuZnAl催化剂合成气制异丁醇反应的影响

摘要

CuZnAl hydrotalcite-like compound were prepared by co-precipitation as catalyst precursor, and it, after calcination, was used to prepare the modified CuZnAl catalysts with different contents of potassium by incipient impregnation. The catalysts were characterized by XRD, H2-TPR, Raman spectroscopy, N2adsorption-desorption and CO-TPD, and their catalytic activities were evaluated for synthesis of higher alcohols form syngas. The results suggest that potassium, as an electron promoter, improves the conversion of CO and has significant effect on the distribution of ZnO on the surface of the catalysts. The electron-donating effect of potassium increases the amount of Cu active sites after reduction and facilitates the adsorption of CO on the surface of active components.Therefore,potassium promotes isobutanol synthesis.%采用共沉淀法制备CuZnAl类水滑石前驱体,焙烧后通过等体积浸渍方法制得K含量不同的改性CuZnAl催化剂.借助XRD、H2-TPR、Raman、N2吸附-脱附和CO-TPD等方法对催化剂进行表征,并将其应用于合成气制备异丁醇的反应中,进行活性评价.结果表明,K作为电子助剂促进CO转化率的提高,同时对催化剂表面ZnO的分布有影响.K的电子效应增加还原后Cu活性中心的数量,有利于CO在活性组分表面的吸附,因而促进异丁醇的生成.