Effect of H₂S/H₂ sulfuration temperature on performance of MoP/SiO₂ catalyst for thioetherification

The MoP/SiO₂ catalyst was prepared from the supported Mo phosphate by the H₂-TPR method and treated with 3%H₂S/H₂ at different temperatures. The as-prepared catalysts were characterized by means of XRD, HRTEM-EDX, XPS, NH₃-TPD, ICP-AES and CO chemisorption and tested for the thioetherification of isoprene and n-butylmercaptan. The effects of sulfuration temperature on the MoP/SiO₂ catalyst structure and thioetherification performance were investigated. The results showed that the MoP phase was still stable even at the sulfuration temperature of 400 ℃. As the sulfuration temperature increased, the acid amount of the catalysts increased while the surface metal site density decreased. As a result, in the thioetherification of isoprene and n-butylmercaptan, the C-S bond hydrogenolysis and the over-hydrogenation of isoprene were suppressed on the sulfurized catalysts, while the olefin polymerization was promoted. Relatively, the MoP/SiO₂ catalyst sulfurized at 120 ℃ had better performance for the thioetherification and the selective hydrogenation of isoprene.