Comparative study of La_1-xCe_xMnO_3+δ perovskites and Mn-Ce mixed oxides for NO catalytic oxidation

Baohuai Zhao^1,2，Rui Ran³，Liu Yang¹，Xiaodong Wu⁴，Zhichun Si⁵，Duan Weng³

1. Institute of Engineering Technology,SINOPEC Catalyst Company2. Key Laboratory of Advanced Materials MOE ,School of Materials Science and Engineering,Tsinghua University3. Key Laboratory of Advanced Materials (MOE),School of Materials Science and Engineering,Tsinghua University4. Key Laboratory of Advanced Materials(MOE),School of Materials Science and Engineering,Tsinghua University5. Advanced Materials Institute,Graduate School at Shenzhen,Tsinghua University

摘 要：A series of La_1-xCe_xMnO_3+δ（x=D,0.05,0.1,0.2,and 0.3） perovskites and Mn-Ce mixed oxides were prepared.Their physico-chemical properties were systematically characterized and the NO oxidation activities of the catalysts were investigated.The La_0.9Ce_0.1MnO_3+δ has the best activity among all of the catalysts,with a maximum NO conversion of 85% at 300℃.The characterization results indicate that the doping of Ce improves the properties of the perovsidtes in terms of the specific surface area,the average valence state of Mn ions,the number of reactive oxygen species and the NO_x desorption behaviors.The Mn-Ce mixed oxide calcined at 500℃ shows a similar NO oxidation activity with La_0.9Ce_0.1MnO_3+δ.However,the activity of the mixed oxide obtained at 750℃ decreases a lot,which results from the loss of active sites and active oxygen species.

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