Park JH  Cho KH  Kim YJ  Shin CH

Vol. 17,  No. 2, pp. 166-174, Jun.  2011

CO oxidation Al-Ce mixed oxide H2-TPR CO-TPR Water gas shift reaction

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The xAl-yCe oxide catalysts with different mol ratios of Al/(Al+Ce) were prepared by a co-precipitation method and Pt supported on xAl-yCe oxide catalysts were synthesized by an incipient wetness impregnation method. The catalysts were characterized by X-ray Diffraction (XRD), N2 sorption, and H2/CO-temperature programmed reduction (H2/CO-TPR) to correlate with catalytic activities in CO oxidation. Among the catalysts studied here, Pt/1Al-9Ce oxide catalyst showed the highest activity in dry and wet reaction conditions and the catalytic activity showed a typical volcano-shape curve with respect to Al/(Al+Ce) mol ratio. When the presence of 5% water vapor in the feed, the temperature of T50% was shifted ca. 30 ℃ to lower temperature region than that in dry condition. From CO-TPR, the desorption peak of CO2 on Pt/1Al-9Ce oxide catalyst showed the highest value and well correlated the catalytic performance. It indicates that the Pt/1Al-9Ce oxide catalyst has a large amount of active sites which can be adsorbed by CO and easy to supplies the needed oxygen. In addition, the amount of pentacoordinated Al3+ sites obtained through 27Al NMR analysis is well correlated the catalytic performance.