Enhanced catalytic performance and promotional effect of molybdenum sulfide cluster-derived catalysts for higher alcohols synthesis from syngas

A series of catalysts were prepared using molybdenum sulfide clusters as precursors and their catalytic performance for higher alcohols synthesis was evaluated. It was found that the cluster precursors could provide well-dispersed MoS2 particles and a number of coordinated unsaturated Mo sites with all the catalysts in varying degrees, which were favorable for the formation of intermediate active phases thereby enhancing catalytic performance. In particular, K-NiMo3Sx catalyst obtained by using heterobimetallic cluster NiMo3S13 as precursor exhibited the highest activity with the space-time-yield (STY) of total alcohols (497 mg/g/h) and the selectivity of higher alcohols (59.71%), which could be attributed to the interaction effect of the Ni promoter and Mo species and the resultant formation of active phase NiMo3Sx. Thus, the most key factor for obtaining highly efficient molybdenum sulfide catalysts was to produce a number of coordinated unsaturated sites, on which abundant NiMoS active phase can be formed and the formation of bulk inactive phase should be avoided.