Effect of KCoMoS2 Catalyst Structures on the Catalytic Performance of Higher Alcohols Synthesis via CO Hydrogenation

Abstract

Different structures of cobalt and potassium modified molybdenum sulfide catalyst (KCoMoS2) were synthesized by hydrothermal synthesis, coprecipitation and reverse microemulsion methods. Nitrogen adsorption, XRD, TEM, XPS and HAADF-STEM-EDS techniques were used to characterize the catalysts structures. The results indicate that the molybdenum sulfide-based catalyst synthesized by the reverse microemulsion method possessed less sheets with small lateral dimensions, while the catalysts prepared by the former two methods contained a higher number of stacking MoS2 layers. In the test of higher alcohol synthesis from CO hydrogenation, it was found that the catalyst synthesized by the reverse microemulsion method exhibited the best CO conversion and C2+OH selectivity among the prepared catalysts. The correlation study between the catalysts structure and the reaction properties implies that the shorter and thinner molybdenum sulfide sheet structure favored for the exposure of the active sites, which, in turn, brought about an enhanced CO conversion and more C2+OH formation.