Hydrogenolysis of dimethyl disulfide in the presence of bimetallic sulfide catalysts

The hydrogenolysis of dimethyl disulfide in the presence of Ni,Mo and Co,Mo bimetallic sulfide catalysts was studied at atmospheric pressure and T = 160–400°C. At T ≤ 200°C, dimethyl disulfide undergoes hydrogenolysis at the S-S bond, yielding methanethiol in 95–100% yield. The selectivity of the reaction decreases with increasing residence time and temperature due to methanethiol undergoing condensation to dimethyl disulfide and hydrogenolysis at the C-S bond to yield methane and hydrogen sulfide. The specific activity of the Co,Mo/Al₂O₃ catalyst in hydrogenolysis at the S-S and C-S bonds is equal to or lower than the total activity of the monometallic catalysts. The Ni,Mo/Al₂O₃ catalyst is twice as active as the Ni/Al₂O₃ + Mo/Al₂O₃ or the cobalt-molybdenum bimetallic catalyst.