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Preparation and Evaluation of Copper–Manganese Oxide as a High-Efficiency Catalyst for CO Oxidation and NO Reduction by CO

2017; American Chemical Society; Volume: 121; Issue: 23 Linguagem: Inglês

10.1021/acs.jpcc.7b02052

1932-7455

Tangkang Liu, Yanyan Yao, Longqing Wei, Zhangfu Shi, Liying Han, Haoxuan Yuan, Bin Li, Lihui Dong, Fan Wang, Chuanzhi Sun,

Copper-based nanomaterials and applications

In this work, highly efficient Cux–Mn composite catalysts (0 ≤ x ≤ 0.20) were synthesized by an improved hydrothermal–citrate complex method and tested in the catalytic total oxidation of CO and the removal of NO by CO. The influence of Cu on manganese oxide materials was characterized by several techniques, including FESEM, HRTEM, XRD, BET analysis, H2 TPR, O2 TPD, XPS, and DRIFTS. Possible reaction mechanisms for the NO + CO model reaction and CO oxidation were also tentatively proposed. The Cu-modified manganese oxide materials showed higher catalytic activity in CO oxidation and the selective catalytic reduction (SCR) of NO with CO than pure MnOx materials. The improved catalytic activity in CO oxidation observed for the copper–manganese oxide catalyst was associated with a greater amount of adsorbed oxygen species and high lattice oxygen mobility due to the formation of a Cu1.5Mn1.5O4 spinel active phase (Cux2+–Mnx3+–[O(y–z)⊙z] species). Furthermore, in terms of the CO-SCR model reaction, the surface-dispersed Cux+–O2––Mny+ active species could be reduced to a Cu+–□–Mn(4–x)+ active species, which was considered to be the primary active component in the reduction of NO by CO. The results of the catalytic performance testing indicated that Cu0.075Mn had the highest catalytic activity in CO oxidation, whereas Cu0.15Mn exhibited the best CO-SCR catalytic performance.