Effect of CeO2 Doping on Structure and Catalytic Performance of Co3O4 Catalyst for Low-Temperature CO Oxidation

The effect of CeO2 doping on structure and catalytic performance of Co3O4 catalyst was studied for low-temperature CO oxidation. The Co3O4 catalyst was prepared by a precipitation method and the CeO2/Co3O4 catalyst was prepared by an impregnation method. Their catalytic performance had been studied with a continuous flowing micro-reactor. The results reveal that the CeO2/Co3O4 catalyst exhibits much better resistance to water vapor poisoning than the Co3O4 catalyst for CO oxidation. The CeO2/Co3O4 catalyst can maintain CO complete conversion at least 8,400 min at 110 °C with 0.6% water vapor in the feed gas, while the Co3O4 catalyst can maintain at 100% for only 100 min. Characterizations with XRD, TEM and TPR suggest that the CeO2/Co3O4 catalyst possesses higher dispersion degree, smaller particles and larger SBET, due to the doping of Ceria, and exists the interaction between CeO2 and Co3O4, which may contribute to the excellent water resistance for low-temperature CO oxidation. Furthermore, the H2 detected in the reactor outlet gas seems to indicate that the water–gas shift reaction is the more direct reason.