Mechanistic studies of methane partial oxidation to syngas over LiNiLaOx/Al2O3 catalyst

Temperature-programmed reduction (TPR) characterization of the LiNiLaOx/Al2 O3 catalyst before or after partial oxidation of methane (POM) reaction and a series of O-2, CH4 and CH4/O-2 pulse reaction experiments over the catal yst under different pretreatments were performed. It was found that CH4 dis sociatively adsorbs on active center nickel producing H-2 and surface carbo n, C(a). The surface carbon reacts with surface lattice oxygen or surface a dsorbed oxygen to produce CO. Because the activation barrier for the reacti on C(a)+ O(a) =CO(a) is the highest among all the elementary reactions, the rate-determining step of the POM may be the reaction C(a) + O(a) =CO(a).