On methanethiol synthesis from H₂S‐containing syngas over K₂MoS₄/SiO₂ catalysts promoted with transition metal oxides

Abstract

The catalysts K₂MoS₄/SiO₂ promoted with transition metal oxides Fe₂O₃, CoO, NiO and MnO₂ were prepared and used to catalyze the synthesis of methanethiol from H₂S‐containing syngas. The results of activity assay show that the catalysts promoted with Fe₂O₃, CoO and NiO can remarkably increase the hour space yield of methanethiol. Nevertheless, MnO₂ was found to have a disadvantageous effect on the selectivity of methanethiol. The results of XRD and XPS characterization indicate that the addition of the transition metal oxides promoters is in favor of the formation of a Mo–S–K active phase and also retards the decomposition of K₂MoS₄ to MoS₂, thereby suppressing both the deep reduction of Mo species and the formation of (S–S)² species, which are reflected by the increment of the concentration ratios of both Mo⁶⁺/Mo⁴⁺ and S²/(S–S)².