Co3O4/CeO2的氧化还原性能及反应条件对其CO氧化活性的影响

采用沉淀氧化法制备了Co₃O₄/CeO₂催化剂。运用XRD、BET和TPR表征手段,考察了不同钴铈比及焙烧温度对钴铈复合氧化物物理及化学性能的影响,并分别在干、湿条件下进行了一氧化碳氧化反应研究。结果表明,与纯的Co₃O₄相比,在不同比例的Co₃O₄/CeO₂均经723 K焙烧的各种催化剂中,钴铈原子比为9∶1的复合氧化物粒径较小,比表面积较大,说明适当比例铈的添加能使Co₃O₄具有较小的粒径。此氧化物经538 K温度焙烧制得的钴铈比为9∶1的复合氧化物中Co₃O₄平均粒径为7.2 nm, BET比表面积为167.6 m²/g。经TPR考察发现其具有最优的氧化还原性能。

Redox property of Co3O4/CeO2 and the effect of reaction conditions on its performance in CO oxidation

Co3O4/CeO2 catalysts were prepared by co-precipitation-oxidation method and characterized by using X-ray diffraction(XRD),surface area(SBET) measurement and temperature-programmed reduction(TPR).The effect of cobalt content in Co3O4/CeO2 on its physical properties and catalytic performance in CO oxidation was investigated under both the humid and dry conditions.The results indicated that the Co3O4/CeO2 composite with a Co/Ce atomic ratio of 9(calcined at 723 K) exhibits much smaller particle size and higher surface area than pure Co3O4;the addition of cerium to Co3O4 is beneficial to obtain Co3O4 with small particle size.The average particle size and BET surface area of Co3O4 in the Co3O4/CeO2 composite(Co/Ce atomic ratio = 9) calcined at 538 K are 7.2 nm and 167.6 m2/g,respectively.Accordingly,the Co3O4/CeO2 composite exhibits excellent redox property.