文献类型：期刊文献

中文题名：CeO_2(110)负载Au纳米颗粒催化CO+NO_x反应的DFT+U研究

英文题名：DFT+U study of the CO+NO_x reaction on a CeO_2(110)-supported Au nanoparticle

作者：张洁[1];龚学庆[1];卢冠忠[1]

机构：[1]华东理工大学结构可控先进功能材料及其制备教育部重点实验室,计算化学中心,工业催化研究所,上海200237

年份：2014

卷号：35

期号：8

起止页码：1305

中文期刊名：催化学报

外文期刊名：Chinese Journal of Catalysis

收录：CSTPCD;;EI(收录号：20143618127297);Scopus;北大核心:【北大核心2011】；CSCD:【CSCD2013_2014】；

基金：supported by the National Basic Research Program of China (973 Program; 2010CB732300; 2011CB808505);the National Natural Science Foundation of China (21322307);Shanghai Rising-Star Program (12QH1400700)~~

语种：中文

中文关键词：密度泛函理论;三效催化剂;二氧化铈;金纳米颗粒;一氧化碳;氮氧化合物;氧化还原反应;电子局域

外文关键词：Density functional theory Three-way catalysis Cerium dioxide Gold nanoparticle Carbon monoxide Nitric oxide Redox reaction Electron localization

摘要：通过在位库伦校正的密度泛函理论(DFT+U)方法计算,我们研究了CO和NOx分子在Au负载CeO2(110)表面的吸附.结果表明,CO在Au纳米颗粒的顶位有很强的吸附能,大约为1.2 eV,而NO在Au纳米颗粒上或者Au与CeO2载体界面处都是弱吸附.然而,当NOx在界面处形成N2O2二聚体之后,通过断裂末端的N–O键能够有效地被降解.纵观整个反应过程,第一步CO+N2O2的反应遵循了Langmuir-Hinshelwood机理,活化能只有0.4 eV,通过形成ONNOCO的中间物种最终产生N2O和CO2.不同的是,第二步消除N2O反应遵循了Eley-Rideal碰撞机理,需要相当高的能垒,约为1.8 eV.通过进一步分析表明,稀土Ce元素独特的电子特性能够使电子从Au上转移并且局域到载体表面的Ce阳离子上,并且有助于形成带负电的N2O2分子.而且Au纳米颗粒有很强的结构流动性,能够促进吸附的CO分子靠近界面处的N2O2并与之反应.
The adsorption and reactions of CO and NOx on a Au6 nanoparticle supported on the CeO2（110） surface have been studied using density functional theory calculations corrected by on‐site Cou‐lomb interactions（DFT ＋ U）. The results show that CO can strongly adsorb on the top site of the Au nanoparticle with an adsorption energy of ～1.2 eV, while the adsorption of NO on both the Au na‐noparticle and the interface between the nanoparticle and the CeO2 support is generally much weaker. However, at the interface, formation of the N2O2 dimer followed by cleavage of the terminal N–O bond is an effective way to decompose NOx. For the complete process, the first step of the CO ＋ N2O2 reaction can readily occur in Langmuir‐Hinshelwood mode with an activation energy of only ～0.4 eV, leading to the formation of N2O and CO2 via an intermediate ONNOCO species. In contrast, the second step to eliminate N2O requires a rather high energy barrier of ～1.8 eV through a Eley‐Rideal type collision reaction. Further analyses show that the unique electronic properties of Ce can induce the electron transfer and localization from supported Au to surface Ce cations, which then promotes the formation of negatively charged N2O2. Moreover, the structural flexibility of the Au nanoparticle also facilitates the adsorbed CO to approach and react with N2O2 at the interface.