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A series of Pd catalysts supported on different materials (SiO2, γ-Al2O3, CeO2, TiO2) were synthesized through precipitation reduction of palladium ions with H2. They exhibited different activity during catalytic oxidation of CO to CO2. With the characterization of N2 physisorption experiment, X-ray diffraction, transmission electron microscopy, temperature-programmed reduction, and CO and O2 multi-pulse experiment, the correlation of catalytic activity and oxygen storage capacity (OSC) of catalyst has been investigated. It was found that the reactivity is largely controlled by the OSC of the catalysts, and thus Pd/CeO2 and Pd/TiO2 were more active than Pd/SiO2 and Pd/Al2O3 for CO oxidation.

Aqueous-phase reforming of 5 wt% ethylene glycol was studied at temperature of 498 K over Pt supported on Al2O3, SiO2, TiO2, CeO2. High selectivity about 90% for generation of hydrogen was observed over the supported Pt catalysts, suggesting that the methanation or the Fischer-Tropsch reactions involving CO/CO2 and H2 does not appear to be important over these catalysts under the present conditions. Compared with Pt/SiO2 and Pt/CeO2, Pt supported on Al2O3 and TiO2 produced measurable amounts of gaseous alkane that may be due to the acidity of the supports. To verify this suppose, the water-gas shift reaction was carried out over the catalysts under the same reaction conditions, and no CH4 was observed over these Pt catalysts. Relatively higher generation rates of hydrogen and carbon dioxide were achieved over Pt/Al2O3 and Pt/SiO2 catalysts.