文献类型：期刊文献

英文题名：Molecular-Level Insight into Selective Catalytic Reduction of NOx with NH3 to N2 over a Highly Efficient Bifunctional Va-MnOx Catalyst at Low Temperature

作者：Xin, Ying[1]; Li, Hao[1]; Zhang, Nana[1]; Li, Qian[1]; Zhang, Zhaoliang[1]; Cao, Xiaoming[2]; Hu, P.[2]; Zheng, Lirong[3]; Anderson, James A.[4]

机构：[1] School of Chemistry and Chemical Engineering, Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials, University of Jinan, Jinan, 250022, China; [2] Centre for Computational Chemistry, Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai, 200237, China; [3] Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China; [4] Surface Chemistry and Catalysis Group, Materials and Chemical Engineering, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom

年份：2018

卷号：8

期号：6

起止页码：4937

外文期刊名：ACS Catalysis

收录：EI(收录号：20181905168429)

语种：英文

外文关键词：Manganese oxide - Air quality - Catalyst activity - Catalyst selectivity - Ammonia - Temperature - Density functional theory - Nitrogen oxides - Sol-gels

摘要：Selective catalytic reduction of NOx with ammonia (SCR) is not only an important model catalytic reaction but is also significant in terms of improving environmental air quality and human health. However, SCR catalysts suffer from low activity and selectivity to N2 at low temperature, which in part may be attributed to our limited understanding of the reaction mechanism. Here, an unambiguous molecular-level mechanism is presented for an improved low-temperature SCR activity using bifunctional catalysts composed of highly active oxides (Mn2O3) for NH3 activation and highly selective vanadates (Mn2V2O7) that promote N2 formation. NH3 is initially activated by Mn2O3 to form an NH2 intermediate. Transfer of NH2 to Mn2V2O7 then takes place, which facilitates the capture of gaseous NO leading to the formation of NH2NO over Mn2V2O7, whereafter NH2NO is efficiently converted to the preferred N2 rather than the undesired byproduct, N2O. The proximity of the two components achieved via sol-gel preparation plays a crucial role in the transfer of active intermediates. ? 2018 American Chemical Society.