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 S_BET, 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.