Performance Exploration of Ni-Doped MoS in CO Hydrogenation to Methanol.

The preparation of methanol chemicals through CO and H gas is a positive measure to achieve carbon neutrality. However, developing catalysts with high selectivity remains a challenge due to the irreversible side reaction of reverse water gas shift (RWGS), and the low-temperature characteristics of CO hydrogenation to methanol. In-plane sulfur vacancies of MoS can be the catalytic active sites for CHOH formation, but the edge vacancies are more inclined to the occurrence of methane. Therefore, MoS and a series of MoS/Ni and MoS/Co catalysts doped with different amounts are prepared by a hydrothermal method. A variety of microscopic characterizations indicate that Ni and Co doping can form NiS and CoS, the existence of these substances can prevent CO and H from contacting the edge S vacancies of MoS, and the selectivity of the main product is improved. DFT calculation illustrates that the larger range of orbital hybridization between Ni and MoS leads to CO activation and the active hydrogen is more prone to surface migration. Under optimized preparation conditions, MoS/Ni exhibits relatively good methanol selectivity. Therefore, this strategy of improving methanol selectivity through metal doping has reference significance for the subsequent research and development of such catalysts.