Influence of MnO2 modification methods on the catalytic performance of CuO/CeO2 for NO reduction by CO
来源期刊：JOURNAL OF RARE EARTHS2014年第2期
论文作者：姚小江 熊燕 孙敬方 高飞 邓昱 汤常金 董林
文章页码：131 - 138
摘 要：In order to investigate the influence of MnO2 modification methods on the catalytic performance of CuO/CeO2 catalyst for NO reduction by CO,two series of catalysts（xCuyMn/Ce and xCu/yMn/Ce） were prepared by co-impregnation and stepwise-impregnation methods,and characterized by means of X-ray diffraction（XRD）,Raman spectra,H2-temperature programmed reduction（H2-TPR）,in situ diffuse reflectance infrared Fourier transform spectra（in situ DRIFTS） techniques.Furthermore,the catalytic performances of these catalysts were evaluated by NO+CO model reaction.The obtained results indicated that:（1） The catalysts acquired by co-impregnation method exhibited stronger interaction owing to the more sufficient contact among each component of the catalysts compared with the catalysts obtained by stepwise-impregnation method,which was beneficial to the improvement of the reduction behavior;（2） The excellent reduction behavior was conducive to the formation of low valence state copper species（Cu+/Cu0） and more oxygen vacancies（especially the surface synergetic oxygen vacancies（SSOV,Cu+-□-Mn（4–x）+）） during the reaction process,which were beneficial to the adsorption of CO species and the dissociation of NO species,respectively,and further promoted the enhancement of the catalytic performance.Finally,in order to further understand the difference between the catalytic performances of these catalysts prepared by co-impregnation and stepwise-impregnation methods,a possible reaction mechanism（schematic diagram） was tentatively proposed.
姚小江1,2，熊燕1,2，孙敬方1,2，高飞2，邓昱2，汤常金1,2，董林1,2
1. Key Laboratory of Mesoscopic Chemistry of MOE,School of Chemistry and Chemical Engineering,Nanjing University2. Jiangsu Key Laboratory of Vehicle Emissions Control,Center of Modern Analysis,Nanjing University
摘 要：In order to investigate the influence of MnO2 modification methods on the catalytic performance of CuO/CeO2 catalyst for NO reduction by CO,two series of catalysts（xCuyMn/Ce and xCu/yMn/Ce） were prepared by co-impregnation and stepwise-impregnation methods,and characterized by means of X-ray diffraction（XRD）,Raman spectra,H2-temperature programmed reduction（H2-TPR）,in situ diffuse reflectance infrared Fourier transform spectra（in situ DRIFTS） techniques.Furthermore,the catalytic performances of these catalysts were evaluated by NO+CO model reaction.The obtained results indicated that:（1） The catalysts acquired by co-impregnation method exhibited stronger interaction owing to the more sufficient contact among each component of the catalysts compared with the catalysts obtained by stepwise-impregnation method,which was beneficial to the improvement of the reduction behavior;（2） The excellent reduction behavior was conducive to the formation of low valence state copper species（Cu+/Cu0） and more oxygen vacancies（especially the surface synergetic oxygen vacancies（SSOV,Cu+-□-Mn（4–x）+）） during the reaction process,which were beneficial to the adsorption of CO species and the dissociation of NO species,respectively,and further promoted the enhancement of the catalytic performance.Finally,in order to further understand the difference between the catalytic performances of these catalysts prepared by co-impregnation and stepwise-impregnation methods,a possible reaction mechanism（schematic diagram） was tentatively proposed.
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