The influence of a support on the activity and selectivity of sulfide catalysts for thiophene hydrogenation to tetrahydrothiophene

Thiophene hydrogenation to tetrahydrothiophene (THT) in the gaseous phase at an elevated temperature and a high hydrogen pressure in the presence of transition metal sulfides supported on carbon, aluminum oxide, silica get, and aluminosilicate was examined. High selectivity for THT formation was exhibited by tungsten, molybdenum, and ruthenium sulfides supported on different carriers, as well as by aluminosilicateor silica gel-supported palladium sulfide. The THT selectivity in the presence of supported palladium and cobalt sulfides increases with increasing Bronsted acidity of the catalyst surface. The lowest rate of THT formation was observed on nickel sulfide, regardless of the support nature, and the highest one was achieved on palladium sulfide supported on different carriers; an especially high activity was displayed by palladium sulfide on aluminosilicate. The catalyst activity is enhanced with increasing dispersion of metal sulfides in the support and upon their partial reduction with hydrogen.