Abstract
A series of CuO/CeO2 catalysts with different CuO loadings was prepared via oxalate thermal decomposition. impregnation method for the CO preferential oxidation(PROX) reaction. The catalyst with 10% CuO loading has the best activity, with the lowest and the widest CO full conversion temperature window of 96-160 degrees C and 100% selectivity to CO2 below 131 degrees C The results indicate that the Cu-Ce solid solution is formed when a small amount of CuO is loaded. However, the increased CuO loading will result in the aggregation of CuO on the surface of CeO2, which is unfavorable to form the solid solution. For the CuO/CeO2 catalysts, the formation of Cu-Ce solid solution can inevitably generate surface oxygen vacancy and Ce3+, which can react with the Cu2+ to produce Cu+ through the balance of Ce3+ + Cu2+reversible arrow Ce4+ + Cu+. As the Cu+ is the active center for the CO PROX, the increased surface Ce3+ content and the strengthened interaction be. tween CuO and CeO2 can enhance the CO PROX activity of t