Tuning the metal–support interaction in supported K-promoted NiMo catalysts for enhanced selectivity and productivity towards higher alcohols in CO hydrogenation

Abstract

Mixed metal oxide (MMO)-supported MoS₂ catalysts with tunable size and morphology of active phases for higher alcohol synthesis (HAS) were prepared by using encapsulated Mo-based precursors with cetyltrimethylammonium bromide (CTAB). The Ni–KMoS/MMO catalysts show enhanced activity and superior selectivity towards higher alcohols to those prepared by the multiple impregnation method and co-impregnation method. That is, the K,Ni–30Mo/MMO catalyst exhibits a high space time yield (STY) of 253 mg per g catalyst per h for C₂₊ alcohols, which is about 3.2 and 1.51 times higher than those of IM-K,Ni–30Mo/MMO and co-IM-K,Ni–30Mo/MMO. The compromise between the dispersion and stacking of supported MoS₂ slabs via adjusting the metal–support interaction is crucial to providing abundant Mo edges for dispersing Ni species to achieve more accessible active sites. The remarkable increase in the number of highly dispersed and contacted NiS_x and Ni–KMoS_x dual active sites will provide highly effective synergism, and thus gives this catalyst enhanced activity and exceptional selectivity towards higher alcohols in CO hydrogenation.