Activity of catalysts in the synthesis of dimethyl sulfide from dimethyl disulfide

Dimethyl disulfide conversion at T = 190–350°C over catalysts containing acid and basic sites is reported. The products of this reaction are dimethyl sulfide, methanethiol, hydrogen sulfide, carbon disulfide, methane, and ethylene. At 190°C, these products form via parallel reactions. At higher temperature of up to 350°C, dimethyl sulfide can form by the condensation of the resulting methanethiol. The strong basic sites of the catalysts are uninvolved in dimethyl sulfide formation. Over catalysts whose surface has only strong protonic or strong Lewis acid sites, dimethyl sulfide formation does take place, but slowly and nonselectively. The highest dimethyl sulfide formation activity and selectivity are shown by catalysts having medium-strength basic sites along with strong protonic and strong Lewis acid sites.