Study of ceria-supported nickel catalyst and effect of yttria doping on carbon dioxide reforming of methane Original Research Article

Carbon dioxide reforming of methane was studied over Ni supported on ceria and yttria-doped ceria (YDC) to seek insight into the effect of catalysis at the metal–support interface. In contrast to the performance of Ni/γ-Al2O3, which displayed very rapid deactivation with time on stream, the rate over the ceria- or YDC-supported catalysts exhibited exceptional enhancement of activity and coking resistivity. The extent of enhancement decreased with increased yttria loading. The enhancement of activity and coking resistivity of the ceria-based catalysts, coupled with the results of temperature-programmed reduction and hydrogenation, suggested the formation of interfacial active centers and the existence of metal–support interaction, which decreased with increased yttria loading. EPR and XPS results provided evidence that the ability of CeO2 to lose its lattice oxygen to form Ce3+ was inhibited with yttria doping. The lattice oxygen of ceria is inferred to have played some positive role in the activation of both CH4 and CO2; such promotion is attributed in part to the availability of Ce3+ species at the metal–support interface.