Synergistic effect of Pd and Ni on resistance to carbon deposition over NiO–MgO solid solution supported Pd catalysts in oxidative steam reforming of methane under pressurized conditions

Effect of Pd loading to NiO–MgO solid solution was investigated on catalytic activity and inhibition of carbon deposition in oxidative steam reforming of methane. Under atmospheric pressure, Pd/Ni0.2Mg0.8O exhibited much higher methane conversion than Ni0.2Mg0.8O and Pd/MgO catalysts by the enhancement of reduction degree of Ni and the formation of Pd–Ni alloy. Under pressurized conditions, 0.1% Pd/Ni0.2Mg0.8O catalyst showed high and stable activity; and the amount of deposited carbon was negligible. In contrast, the deactivation was clearly observed over Ni0.2Mg0.8O, Pd/MgO and other Pd/Ni0.2Mg0.8O catalysts, and the deactivation rate was closely related to the amount of deposited carbon.