Preparation, characterization and performance of Pt/CeO2-ZrO2 water gas shift catalyst

CeO 2-ZrO 2 composite oxide with different Ce/Zr ratios was prepared by co-precipitation and a series of Pt/CeO 2-ZrO 2 catalyst samples for water gas shift reaction (WGS) was prepared by impregnation of CeO 2-ZrO 2 with chloroplatinic acid solution. The activity of these catalyst samples was measured in simulated reforming gas. The parameters of preparation and operation of the catalyst were investigated by comparing CO conversion at different temperatures, space velocities and steam/gas ratios. The optimized composition of the catalyst was attained by adjusting the content of Zr and Pt. The catalyst samples were active in a wider temperature range than the traditional Cu-based low temperature shift catalysts, but their activity was lower than that of Cu-based catalyst at lower temperature. The Pt/CeO 2-ZrO 2 may be a good candidate for the onboard hydrogen production because it is stable when exposed to air at high temperature. The CO conversion decreased with increasing space velocity, and increased with increasing steam/gas ratio. The Pt/Ce 0.8Zr 0.2O 2 catalyst showed the highest activity among the catalyst samples. The activity of the catalyst increased with increasing Pt loading when w(Pt)0.6%. The XRD result indicated that the solid solution was formed in the CeO 2-ZrO 2 composite oxide. The activity of the catalyst can be improved by increasing the Pt atoms on the support surface.