Abstract
Catalytic oxidation is the most efficient method of minimizing the emissions of harmful pollutants and greenhouse gases. In this study, ZrO(2)-supported Pd catalysts are investigated for the catalytic oxidation of methane and ethylene. Pd/Y(2)O(3)-stabilized ZrO(2) (Pd/YSZ) catalysts show attractive catalytic activity for methane and ethylene oxidation. The ZrO(2) support containing up to 8 mol% Y(2)O(3) improves the water resistance and hydrothermal stability of the catalyst. All catalysts are characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), O(2)-temperature-programmed desorption (O(2)-TPD), and CO-chemisorption techniques. It shows that high Pd dispersion and Pd-PdO reciprocation on the Pd/YSZ catalyst results in relatively high stability. In situ diffuse reflectance infrared Fourier-transform (DRIFT) experiments are performed to study the reaction over the surface of the catalyst. Compared with bimetallic catalysts (Pd : Pt), the same amounts of Pd and Pt supported on ZrO(2) and Y(2)O(3)-stabilized ZrO(2) catalysts show enhanced activity for methane and ethylene oxidation, respectively. A mixed hydrocarbon feed, containing methane and ethylene, lowers the CH(4) light-off temperature by approximately 80 °C. This shows that ethylene addition has a promotional effect on the light-off temperature of methane.