Improved Low-Temperature Activity of CuO-CeO2-ZrO2 Catalysts for Preferential Oxidation of CO in H2-Rich Streams

In this work, CuO-CeO2-ZrO2 catalysts for CO preferential oxidation have been prepared by ultrasound assisted reverse coprecipitation and slow coprecipitation, and characterized via BET, XRD, XPS and H-2-TPR techniques, respectively. It is found that the catalyst prepared with ultrasound assisted reverse coprecipitation preserves large specific surface area, fine crystalline grain and high dispersion of active copper species. Meanwhile, the reducibility is improved significantly and more active copper species and oxygen vacancies are formed in the copper-ceria boundaries. The ultrasound assisted reverse coprecipitation prepared CuO-CeO2-ZrO2 catalyst exhibits superior low-temperature activity and CO2 selectivity, over which the temperature responding to 50 % CO conversion is as low as 67 A degrees C, and the temperature window of full CO conversion is significantly widen from 100 to 160 A degrees C. The ultrasound assisted reverse coprecipitation prepared CuO-CeO2-ZrO2 catalyst exhibits superior low-temperature activity for CO preferential oxidation and wide temperature window of full CO conversion comparing with the catalyst prepared with slow coprecipitation. [GRAPHICS]