Complete oxidation of methane and carbon monoxide on supported palladium and platinum catalysts

Palladium and platinum supported by CeO2, ZrO2 and Al2O3 have been prepared by conventional impregnation method. The effect of support on catalytic ac tivity on oxidation of CO and methane has been studied. The activity of the supported Pd catalyst is much higher than that of the supported Pt catalys t. The catalytic activity depends on the nature of the support; the sequenc e for supported Pd and Pt catalyst being CeO2 > ZrO2 > Al2O3. For both CO a nd methane oxidation, Pd/CeO2 shows highest activity with a light-off tempe rature at 45 degrees and 310 degrees C respectively, with no apparent decay . This is mostly due to the superoxide species over CeO2. Pd/ZrO2, PdVAl2O3 and Pt/CeO2 catalysts exhibit apparent deactivation. The heat-stability of Pd/CeO2 is inferior to Pd/Al2O3 catalyst, but the oxidation activity of Pd /CeO2 catalyst for CO and methane is higher than that of Pd/Al2O3 after cal cination at 1200 degrees C for 4h.