净化柴油机尾气的Sm(Y,Tb)Mn_2O_5莫来石氧化NO的机理研究
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- 英文论文题名：Identifying Descriptor of Governing NO Oxidation on Mullite Sm(Y,Tb)Mn_2O_5 for Diesel Exhaust Cleaning
- 论文作者：李好博 ; 陈海军 ; 卢峰 ; 王卫超
- 英文论文作者：Hao-Bo Li ; Haijun Chen ; Feng Lu ; Weichao Wang ; Department of Electronics ; Nankai University ; Dalian Institute of Chemical Physics ; Chinese Academy of Sciences
- 年：2016
- 作者机构：南开大学电子信息与光学工程学院;中国科学院大连化物所;
- 论文关键词：NO氧化 ; 莫来石氧化物 ; p-d轨道杂化
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第十五分会：表界面结构调控与催化
- 语种：中文
- 分类号：X701;O643.36
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第十五分会 ; 表界面结构调控与催化
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：1
- 文件大小：181k
- 原文格式：D
- 会议级别：全国
摘要
快速选择性催化还原(fast-SCR)技术是柴油机尾气氮氧污染物净化处理的有效手段,其核心是利用铂金催化剂把NO_x转化成对环境没有污染的氮气。我们以前的工作[1]发现,锰基莫来石氧化物A(Sm,Gd)Mn_2O_5和铂金相比具有很大的转换优势。但是如何理解莫来石氧化物高效的催化活性,目前位置,并没有很好的研究。本报告中,利用X-射线吸收谱和分子轨道理论,发现当变化莫来石A位元素(Sm,Y,Tb)时,3d电子轨道占据并没有对催化活性有明显的线性关系;相反,我们发现八面体中Mn和晶格中氧的p-d轨道杂化强度和x-吸收谱吸收强度显示出很好的依赖关系,通过该杂化过程,催化活性点四面体Mn原子和外界的O*相互作用可以得到调解和优化,从而达到催化性能的最优化[2]。
The current fast selective catalytic reduction(fast-SCR) technology shows an effectiveness of converting the diesel engine generated nitrogen oxides NO_x to environmentally benign nitrogen(N_2) with the aid of the precious metal catalyst platinum.Driven by previous finding of the low-cost mullite's great superiority over Pt in term of NO oxidation,a series of Mn-based oxides Sm(Y,Tb)Mn_2O_5 materials are synthesized to identify a general descriptor to govern the catalytic performance.Utilizing soft X-ray absorption characterization and molecular orbital theory,here,we show that catalytic activity difference presents little dependence on the 3d electron occupancy when varying A site element(Sm,Tb,Y).Instead,strong p-d hybridization between lattice O and octahedral Mn leads to weak bonding strength between external O* and pyramid Mn and essentially increases the catalytic behavior of converting NO to NO_2.
The current fast selective catalytic reduction(fast-SCR) technology shows an effectiveness of converting the diesel engine generated nitrogen oxides NO_x to environmentally benign nitrogen(N_2) with the aid of the precious metal catalyst platinum.Driven by previous finding of the low-cost mullite's great superiority over Pt in term of NO oxidation,a series of Mn-based oxides Sm(Y,Tb)Mn_2O_5 materials are synthesized to identify a general descriptor to govern the catalytic performance.Utilizing soft X-ray absorption characterization and molecular orbital theory,here,we show that catalytic activity difference presents little dependence on the 3d electron occupancy when varying A site element(Sm,Tb,Y).Instead,strong p-d hybridization between lattice O and octahedral Mn leads to weak bonding strength between external O* and pyramid Mn and essentially increases the catalytic behavior of converting NO to NO_2.
引文
[1]Wang,W;M.Geoffrey;Kapur,N;Yuan G.;Shan,B.;Nguyen M.;Graham,U.;Davis B.;Jacobs,G.;Cho,K.;Hao,X.,Science,2012,337;832.
[2]W.Wang,et al,Catalysis Science&Technology,2016,作者一,作者二,作者三,作者四.杂志名称,2010,26(4):1051
[2]W.Wang,et al,Catalysis Science&Technology,2016,作者一,作者二,作者三,作者四.杂志名称,2010,26(4):1051