Catalytic partial oxidation of methane and isotopic oxygen exchange reactions over 18O labeled Rh/Gadolinium doped ceria

► Rh/(Ce0.91Gd0.09)O2-x showed higher oxygen exchange rates than Rh/γ-Al2O3 during the isotopic exchange experiments. ► The oxygen exchange rate between the gas and the solid phase is limited by the oxygen mobility in/on the catalyst. ► During the partial oxidation of methane, CO and Hydrogen are generated through two different mechanisms.