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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. [ABSTRACT FROM AUTHOR]

• Collaborative removal and recycling treatment of CO and H 2 S into CH 3 SH is promising. • MSI, SMSI and EMSI are constructed and investigated for the synthesis of CH 3 SH. • SMSI favors the production of smaller sizes of K-MoS 2 particles and enhances the CH 3 SH formation rate. • EMSI is not in favor to the synthesis of CH 3 SH from CO/H 2 /H 2 S mixtures. Modulation of the metal-support interactions (MSI) is an effective means to improve the performance of supported catalysts, but the role of the metal-support effect in the synthesis of CH 3 SH from CO/H 2 /H 2 S mixtures has not been recognized. Here, three different interactions, namely weak MSI, strong MSI and electronic MSI are constructed over K-promoted MoS 2 -base catalysts and investigated for the synthesis of CH 3 SH. The catalytic activity experiments show that the K-Mo catalyst with strong MSI has the highest formation rate toward CH 3 SH, while the K-Mo catalyst with electronic MSI instead shows the worst formation rate toward CH 3 SH. The characterizations suggest that the strong MSI facilitates the enhancement of Mo-S bond strength and the production of few layers, shorter slab and ordered K-MoS 2 particles. The former benefits the formation and stabilization of C-S intermediate species and subsequent hydrogenation to CH 3 SH, while the latter promotes the generation of more Mo-coordinatively unsaturated sites (Mo-CUS) and thus facilitates the first-step adsorption and activation of reactants. In contrast, electronic MSI weakens the strength of the Mo-S bond, which inhibits the generation of C-S intermediate species. On the other hand, the presence of electronic MSI leads to the generation of Mo-O v -Ti interfacial sites, which is favorable for the hydrogenolysis of CH 3 SH to CH 4. This work provides an insight into the construction and selection of metal-support interactions for heterogeneous catalysis. [ABSTRACT FROM AUTHOR]