曲振平

个人信息Personal Information

教授

博士生导师

硕士生导师

性别:女

毕业院校:中科院大连化学物理研究所

学位:博士

所在单位:环境学院

学科:环境科学与工程. 环境工程. 环境科学

办公地点:环境楼B511

电子邮箱:quzhenping@dlut.edu.cn

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Role of the support on the behavior of Ag-based catalysts for NH3 selective catalytic oxidation (NH3-SCO)

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论文类型:期刊论文

发表时间:2014-10-15

发表刊物:APPLIED SURFACE SCIENCE

收录刊物:SCIE、EI

卷号:316

期号:1

页面范围:373-379

ISSN号:0169-4332

关键字:NH3-SCO; UV-vis; Silver species; Support; N-2/N2O formation

摘要:In this work four supports with different textural properties (Al2O3, SiO2, NaY and TiO2) are used to evaluate the formation of different silver species and their effect on the NH3-SCO performance. Characterization analyses have shown that the predominant Ag-0 species and the oxidized Ag species Ag+ and Ag-n(delta+)) are located on the four catalysts with different ratio of Ag-0/oxidized Ag. Small Ag-0 particle with high dispersion which is obtained on 10 wt% Ag/Al2O3 (5 nm, Ag-0 ratio = 97.7%) shows an excellent catalytic performance for SCO reaction at low temperatures a complete NH3 conversion at 180 degrees C and a high N-2 selectivity of 89%). In addition, a certain amount of oxidized Ag species formed on the catalysts, especially for the NaY and SiO2 support, as well as the surface acidity of catalysts have also been found to play an important role in the enhanced N-2 selectivity above 140 degrees C by promoting iSCR reaction involving NO as an intermediate for N-2 formation. A model to relate the silver species with the performance of NH3-SCO is proposed, which is very significant for the further optimization of the catalyst (e.g. choosing a suitable support) for NH3-SCO reaction and its practical application in the future. (C) 2014 Elsevier B.V. All rights reserved.