文献类型：期刊文献

中文题名：Insights into the selective catalytic reduction of NO by NH_3 over Mn_3O_4(110):a DFT study coupled with microkinetic analysis

英文题名：Insights into the selective catalytic reduction of NO by NH_3 over Mn_3O_4(110):a DFT study coupled with microkinetic analysis

作者：Mingxia Yang[1];Haiyang Yuan[1];Haifeng Wang[1];P.Hu[1,2]

机构：[1]Key Laboratory for Advanced Materials, Center for Computational Chemistry and Research Institute of Industrial Catalysis, School of Chemistry and Molecular Engineering, East China University of Science and Technology;[2]School of Chemistry and Chemical Engineering, The Queen's University of Belfast

年份：2018

卷号：61

期号：4

起止页码：457

中文期刊名：Science China Chemistry

外文期刊名：中国科学（化学英文版）

收录：Scopus;CSCD:【CSCD2017_2018】；

基金：supported by the National Natural Science Foundation of China(21333003,21622305);Young Elite Scientist Sponsorship Program by China Association for Science and Technology(YESS20150131);"Shu Guang"project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation(13SG30);the Fundamental Research Funds for the Central Universities(WJ616007)

语种：英文

中文关键词：nitric oxide; selective catalytic reduction; Mn3O4; reaction mechanism; density functional theory

外文关键词：Mn3O4;催化剂;NH3;DFT;表面结构;NH2;污染物质;环境问题

摘要：Nitric oxide(NO_x), as one of the main pollutants, can contribute to a series of environmental problems, and to date the selective catalytic reduction(SCR) of NO_x with NH_3 in the presence of excess of O_2 over the catalysts has served as one of the most effective methods, in which Mn-based catalysts have been widely studied owing to their excellent low-temperature activity toward NH3-SCR. However, the related structure-activity relation was not satisfactorily explored at the atomic level. By virtue of DFT+U calculations together with microkinetic analysis, we systemically investigate the selective catalytic reduction process of NO with NH_3 over Mn_3 O_4(110), and identify the crucial thermodynamic and kinetic factors that limit the catalytic activity and selectivity.It is found that NH3 prefers to adsorb on the Lewis acid site and then dehydrogenates into NH_2~* assisted by either the two-or three-fold lattice oxygen; NH_2~* would then react with the gaseous NO to form an important intermediate NH_2 NO that prefers to convert into N_2 O rather than N_2 after the sequential dehydrogenation, while the residual H atoms interact with O_2 and left the surface in the form of H_2 O. The rate-determining step is proposed to be the coupling reaction between NH_2~* and gaseous NO.Regarding the complex surface structure of Mn_3 O_4(110),the main active sites are quantitatively revealed to be O_(3 c) and Mn_(4 c).
Nitric oxide（Nox）, as one of the main pollutants, can contribute to a series of environmental problems, and to date the selective catalytic reduction（SCR） of NOx with NH3 in the presence of excess of O2 over the catalysts has served as one of the most effective methods, in which Mn-based catalysts have been widely studied owing to their excellent low-temperature activity toward NH3-SCR. However, the related structure-activity relation was not satisfactorily explored at the atomic level. By virtue of DFT＋U calculations together with microkinetic analysis, we systemically investigate the selective catalytic reduction process of NO with NH3 over Mn3 O4（110）, and identify the crucial thermodynamic and kinetic factors that limit the catalytic activity and selectivity.It is found that NH3 prefers to adsorb on the Lewis acid site and then dehydrogenates into NH2^＊ assisted by either the two-or three-fold lattice oxygen; NH2^＊ would then react with the gaseous NO to form an important intermediate NH2 NO that prefers to convert into N2 O rather than N2 after the sequential dehydrogenation, while the residual H atoms interact with O2 and left the surface in the form of H2 O. The rate-determining step is proposed to be the coupling reaction between NH2^＊ and gaseous NO.Regarding the complex surface structure of Mn3 O4（110）,the main active sites are quantitatively revealed to be O（3 c） and Mn（4 c）.