Partial oxidation and CO2 reforming of methane on Pt/Al2O3, Pt/ZrO2, and Pt/Ce–ZrO2 catalysts

The partial oxidation and CO2 reforming of methane were studied on Pt/Al2O3, Pt/ZrO2, and Pt/Ce–ZrO2 catalysts. The reducibility and the oxygen transfer capacity were evaluated by oxygen storage capacity (OSC). The effect of the support on the cleaning mechanism of the catalyst surface was investigated by the sequence of CH4/O2 and CH4/CO2 pulses. The Pt/Ce–ZrO2 catalyst showed the highest stability on both partial oxidation and CO2 reforming of methane. The results were explained by the higher reducibility and oxygen storage/release capacity of Pt/Ce–ZrO2 catalysts, which allowed a continuous removal of carbonaceous deposits from the active sites, favoring the stability of the catalysts, as revealed by the CH4/O2 and CH4/CO2 pulses. For Pt/Al2O3 and Pt/ZrO2 catalysts, the increase of carbon deposits around or near the metal particle inhibits the CO2 dissociation on CO2 reforming of methane. This effect on the CO2 reforming of methane affects the partial oxidation of methane, which comprehends two steps: combustion of methane and CO2 and steam reforming of unreacted methane.