Low-temperature CO oxidation over Co₃O₄-based catalysts: Significant promoting effect of Bi₂O₃ on Co₃O₄ catalyst

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• 作者：Yang Lou ; Li Wang ; Zhenyang Zhao ; Yanhui Zhang ; Zhigang Zhang ; Guanzhong Lu ; Yun Guo ; Yanglong Guo
• 关键词：Low-temperature CO oxidation ; Oxygen vacancy ; Co3O4 ; Bi2O3 ; O2 activation
• 刊名：Applied Catalysis B: Environmental
• 出版年：2014
• 出版时间：March, 2014
• 年：2014
• 卷：146
• 期：Complete
• 页码：43-49
• 全文大小：774 K

文摘

The modification of Co₃O₄ by Bi₂O₃ significantly enhanced its catalytic performance for CO oxidation. The 20 wt. % Bi₂O₃-Co₃O₄ exhibited the best catalytic performance. The results of H₂-TPR and CO-TPR revealed that the mobility of oxygen was accelerated greatly and the ability of low-temperature oxygen activation was the crucial factor to improve the catalytic performance. Bi₂O₃ entered the lattice of Co₃O₄ caused the structural defect and lattice distortion, which should be the origin of the high O₂ activation ability and mobility. Structure-performance correlation demonstrated that the low-temperature oxygen activation was dependent on the defective degree of structure, which was determined by the content of Bi₂O₃. The catalytic behaviors under different reaction conditions revealed that CO could effectively adsorb on the surface active sites and CO₂ could competitively adsorb on the active sites. The ability to supply the active O₂ species was suggested to be a key step. The kinetic data showed not only the amount of surface active sites were increased on the surface of Co₃O₄ but also the catalytic ability of single active site was enhanced greatly.