Modulating the sulfurization procedure to decrease by-product formation for one-step catalytic synthesis of sulfur-containing chemicals

Abstract

The one-step synthesis of sulfur-containing chemicals, methanethiol (CH₃SH), from syngas and hydrogen sullfide (H₂S) mixtures shows the enormous potential for extending the application of both C₁ chemistry and sulfur resource recycling and utilization. However, directionally regulating the reaction pathway for synthesizing target sulfur-containing chemicals remain challenging owing to the presence of multiple reactants and the following various competitive side reactions. Herein, we propose a facile and simple sulfurization procedure-dependent strategies to regulate the Mo-S(O) bond strength of K-MoS₂ catalysts for highly selective CO-to-CH₃SH catalysis. The activity tests, the characterization results and in situ DRIFTS technique demonstrate that a slower sulfurization heating rate and abundant-reduced sulfurization atmosphere facilitate the formation of K-intercalated 1 T-MoS₂ phase, which possesses a weaker Mo-S(O) bond than that of CO bond in CO molecules. This weakened bonding pattern is advantageous to the CO non-dissociative activation to from ^⁎COS species, and the further hydrogenation of adsorbed ^⁎COS and ^⁎CH_xS species to main product of CH₃SH. Otherwise, the strong bonding of Mo-S(O) bond with CO molecule over K-decorated 2H-MoS₂ phase can lead to the breakage of CO bond, promoting the formation of CH_x species and the occurrence of methanation side reaction. This strategy could provide the useful guidance for the fine regulation of the main and side reaction pathway for producing important chemicals from carbon and sulfur basic materials.