限域FeO体系的界面与尺寸效应
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- 英文论文题名：CO oxidation at the nanoscale interface:size and interface effects
- 论文作者：杨帆 ; 刘云 ; 肖建平 ; 于良 ; 刘庆飞 ; 张毅 ; 宁艳晓 ; 陈浩 ; 包信和
- 英文论文作者：Fan Yang ; Yun Liu ; Jianping Xiao ; Liang Yu ; Qingfei Liu ; Yi Zhang ; Yanxiao Ning ; Hao Chen ; Xinhe Bao ; State Key Laboratory of Catalysis ; Dalian Institute of Chemical Physics
- 年：2016
- 作者机构：中国科学院大连化学物理研究所;
- 论文关键词：金属/氧化物界面 ; 低温CO氧化 ; 界面限域效应 ; 尺寸效应
- 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：O614.811;TB383.1
- 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：148k
- 原文格式：D
- 会议级别：全国
摘要
界面效应与尺寸效应是多相催化中两类最基本而广泛存在的现象(1),也是调控催化活性与选择性的两种最有效的手段。二者在原子/电子结构尺度的本质特征还有待深入的研究和理解,而早期的表面催化研究由于局限于单晶表面也难以涉及这两种效应。利用分子束外延生长,我们现在可以在不同金属基底上构筑原子尺度结构规整的氧化物纳米结构,这为模型催化研究界面与尺寸效应铺平了道路。本报告主要讨论限域Fe O纳米结构的界面与尺寸限域效应。Fe O/Pt界面是近年所发现的具有低温CO氧化活性的一类金属/氧化物界面催化体系的典型代表(2,3),可有效消除富氢环境下Pt系催化剂的CO中毒问题,然而Fe O在其中所起的具体作用尚缺乏分子尺度的实验观察和理解。运用扫描隧道显微镜,高分辨电子能量损失谱和能谱等手段,同时结合理论计算,我们对Fe O/Pt(111)界面的CO氧化反应实现了基元反应和反应动力学的分子尺度理解。在此基础上,通过对比不同尺寸Fe O纳米结构的界面结构和界面催化化学,我们探讨了界面和尺寸限域效应对活性中心催化过程的影响和调控。
Despite tremendous importance,the metal-oxide interface remains poorly understood in catalysis since interfacial sites are of trace amount and difficult to measure.Recently,the Fe O-Pt interface has been suggested to exhibit remarkable activity in the preferential oxidation of CO(PROX) in excess H21,2.Combining microscopic and spectroscopic methods,CO oxidation was investigated at the Pt-Fe O interface,to understand the mechanism of low temperature CO oxidation and the catalytic property of the metal-oxide interface in general.Size effect was further investigated using different-sized Fe O NPs as the model system.Although our capability to measure the size-dependent geometric or electronic properties has reached the atomic level,these properties were usually measured statically and in the absence of reactive gases.By resolving the interaction between NPs and reactants at the atomic level,we demonstrate a dynamic size effect that could govern the chemical properties of NPs and the catalytic process.
Despite tremendous importance,the metal-oxide interface remains poorly understood in catalysis since interfacial sites are of trace amount and difficult to measure.Recently,the Fe O-Pt interface has been suggested to exhibit remarkable activity in the preferential oxidation of CO(PROX) in excess H21,2.Combining microscopic and spectroscopic methods,CO oxidation was investigated at the Pt-Fe O interface,to understand the mechanism of low temperature CO oxidation and the catalytic property of the metal-oxide interface in general.Size effect was further investigated using different-sized Fe O NPs as the model system.Although our capability to measure the size-dependent geometric or electronic properties has reached the atomic level,these properties were usually measured statically and in the absence of reactive gases.By resolving the interaction between NPs and reactants at the atomic level,we demonstrate a dynamic size effect that could govern the chemical properties of NPs and the catalytic process.
引文
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2.Fu Q,Li W-X,Yao Y,et al.Interface-confined ferrous centers for catalytic oxidation.Science.2010;328:1141-4.
3.Fu Q,Yang F,Bao X.Interface-confined oxide nanostructures for catalytic oxidation reactions.Acc Chem Res.2013;46:1692-701.