The Influence of Sulfurization and Carbonization on Mo-Based Catalysts for CH3SH Synthesis

Abstract

Sulfur-resistant Mo-based catalysts have become promising for the one-step synthesis of methanethiol (CH3SH) from CO/H2/H2S, but the low reactant conversion and poor product selectivity have constrained its development. Herein, we synthesized K-MoS2/Al2O3 and K-Mo2C/Al2O3 catalysts via the sulfurization and carbonization of K-Mo-based catalysts in the oxidized state, respectively. During the synthesis of CH3SH, both K-Mo2C/Al2O3 and K-MoS2/Al2O3 showed excellent catalytic performance, and the activity of the former is superior to that of the latter. The effect of different treatments on the catalytic performance of Mo-based catalysts was investigated by XRD, BET, Raman spectroscopy, H2-TPR, and reactants-TPD characterization. The results showed that the sulfide-treated sample showed stronger metal-support interactions and contributed to the formation of K2S, which exposed more active sites and stabilized the formation of C-S bonds. Carbonized samples enhanced the activation of H2, which promoted the hydrogenation of the intermediate species of carbonyl sulfide (COS) and thus improved the selectivity of CH3SH.