EXAFS characterization of new active phases for catalytic hydrotreatment:: Two cations disulfide layers in the MoxW(1-x)S2 lamellar solid solution

Bulk and alumina-supported Mo0.5W0.5S2 compounds were prepared. The presence of both molybdenum and tungsten in every [MS2] layer (intralayer solid solution) was evidenced using EXAFS spectroscopy, the only local method which can provide such relevant structural information. The catalytic interest of such solid solution is to provide a continuous variation of M-S bond strength which is considered as the key parameter of the catalytic activity transition metal sulfides. The solid solution is maintained after promotion by Ni either on unsupported or supported state.