The effect of alkali metals doping on properties of CuMgCe for isobutanol synthesis from syngas

Abstract

Four types of alkali metals Li, Na, K and Cs carbonate doped CuMgCe catalysts were prepared by an incipient wetness impregnation method, and the effect of alkali metals doping on the catalytic performance of catalyst for isobutanol synthesis from syngas was studied. Only the doping of K and Cs improved isobutanol selectivity, and the catalytic performance of K-CMC was better. All the catalysts characterized by XRD, BET, SEM, TEM, XPS, H2-TPR, CO-TPD, CO2-TPD and NH3-TPD to further reveal the effect of alkali metals on catalysts for isobutanol synthesis. We found that the alkali metals doping reduced the reducibility of the catalysts, but increased the strength and density of basic sites and reduced the density of acidic sites, thereby leading to diverse catalytic performance of the catalysts for isobutanol synthesis. Compared with K-CMC, the insufficient performance of Cs-CMC was attributed to CO2 oxidation of Cu and CO2 neutralization of basic sites.