Yttria-stabilized zirconia supported platinum catalysts (Pt/YSZs) for CH4/CO2 reforming

Yttria-stabilized zirconia (YSZs) samples with various amounts of yttrium were prepared, characterized, and used as supports for preparing Pt/YSZ catalysts. CH4/CO2 reforming over the Pt/YSZ catalysts was examined and compared with the results over Pt/Al2O3 and Pt/SiO2 catalysts. Analysis of TPR revealed that the reduction temperature range of the Pt/YSZ catalysts was much lower than that of the Pt/Al2O3 and Pt/SiO2 catalysts. For CH4/CO2 reforming at 600 degreesC, the Pt/YSZ catalysts showed a higher steady state conversion and significantly better stability than the Pt/Al2O3 and Pt/SiO2 catalysts. These results were attributed to the enhancing of adsorption, activation and dissociation of CO2 on the YSZ. The optimum dosage of yttrium in YSZ for the CH4/CO2 reforming reaction was 9.8 mol% (Y/(Zr + Y)). Additionally, YSZ(9.8) could be homogeneously spread on the SiO2 and was more stable than the YSZ(9.8) for the CH4/CO2 reforming at temperatures above 700 degreesC. (C) 2001 Elsevier Science B.V. All rights reserved.