Catalytic activities of Mo-modified Ni/Al2O3 catalysts for thioetherification of mercaptans and di-olefins in fluid catalytic cracking naphtha

A series of molybdenum-modified Ni/Al2O3 catalysts were prepared, and their catalytic activities and stabilities for thioetherification of mercaptans and di-olefins in fluid catalytic cracking (FCC) naphtha were investigated. The sulfided catalyst samples were characterized by a range of physical techniques. The results showed that the addition of Mo to Ni catalysts could improve the degree of dispersion of Ni species in the carrier, inhibit the formation of NiAl2O4 crystallites, enhance the presulfidation degree of the metals, and change the chemical environment and electronic structure of Ni. These effects could significantly improve the activity of the Ni/Al2O3 catalysts for thioetherification in FCC naphtha. Furthermore, addition of a small amount of Mo improved the di-olefin selective hydrogenation ability of the Ni/Al2O3 catalyst and significantly reduced coke formation during the reaction.