A comparative study of different doped metal cations on the reduction, adsorption and activity of CuO/Ce0.67M0.33O2 (M = Zr4 , Sn4 , Ti4 ) catalysts for NO plus CO reaction

作者：Yao, Xiaojiang; Yu, Qiang; Ji, Zeyang; Lv, Yuanyuan; Cao, Yuan; Tang, Changjin; Gao, Fei; Dong, Lin^*; Chen, Yi

来源：Applied Catalysis B: Environmental , 2013, 130: 293-304.

DOI：10.1016/j.apcatb.2012.11.020

• Ceria-based solid solution
• Dopant
• Electronegativity
• Copper-based catalyst
• NO plus CO reaction

A series of ceria-based solid solutions (Ce0.67Zr0.33O2, Ce0.67Sn0.33O2, Ce0.67Ti0.33O2) were synthesized by inverse co-precipitation, and then used as supports to prepare CuO/Ce0.67M0.33O2 (M = Zr4 , Sn4 , Ti4 ) catalysts through wetness impregnation method. The obtained samples were investigated in detail by means of XRD, LRS, N-2-physisorption, H-2-TPR, XRF, XPS and in situ FT-IR techniques. The catalytic reduction of NO by CO as a model reaction was chosen to evaluate the catalytic performance of these samples. These results suggest that: (1) the reduction of CuO/Ce0.67Zr0.33O2 is easier than CuO/Ce0.67Sn0.33O2 and CuO/Ce0.67Ti0.33O2 catalysts, which may be attributed to the difference in the electronegativity of dopant; (2) the reduced state Cu is present in CuO/Ce0.67Zr0.33O2 at ambient temperature due to the shifting of redox equilibrium (Cu2 Ce3 <-> Cu Ce4 ) to right; (3) the adsorbed NO species on CuO/Ce0.67Zr0.33O2 are more liable to desorb/transform/decompose than those on CuO/Ce0.67Sn0.33O2 and CuO/Ce0.67Ti0.33O2 samples. The results of catalytic performance show that Cu /Cu-0 species play a key role in NO reduction by CO, and the activity is mainly related to the electronegativity of dopant, the reduction and adsorption behaviors of these catalysts. Furthermore, a possible reaction mechanism (schematic diagram) is tentatively proposed to understand this reaction.

• 出版日期2013-2-7
• 单位南京大学