Reactivity of permeating hydrogen with thiophene on a palladium membrane

The reactivity of hydrogen atoms supplied by permeating through a palladium membrane was investigated for hydrodesulfurization of thiophene by comparison with that of hydrogen atoms supplied by dissociatively adsorbing on the palladium membrane from the gas phase. A system with hydrogen atoms permeating through the palladium bulk gave higher desulfurization activities as compared to a system with hydrogen atoms co-adsorbing with thiophene molecules on the membrane surface. With the hydrogen permeating system, thiophene molecules adsorbed on the surface were hydrogenated by hydrogen atoms supplied not only through the surface but also from the bulk of the membrane. q1998 Elsevier Science B.V.