Preferential CO oxidation (CO-PROX) catalyzed by CuO supported on nanocrystalline CeO2 prepared by a freeze-drying method

CuO supported on CeO2, Ce0.8Zr0.2O2 and Ce0.8Al0.2O2 based catalysts with 6 wt.% of copper were synthesized and tested in the preferential oxidation of CO in a H2-rich stream (CO-PROX). Three nanocrystalline supports, CeO2 and solid solutions of modified CeO2 with zirconium and aluminium were prepared by a freeze-drying method. CuO was supported by incipient wetness impregnation and calcination at 400 ºC. All the prepared catalysts resulted active in the CO-PROX reaction and selective to CO2 at low reaction temperature, being the catalyst supported on CeO2 the more active and stable. The influence of the presence of CO2 and H2O was also studied.