Ceria reoxidation by CO2: A model study
Ceria reoxidation by CO2: A model study
复制标题
DOI：
10.1016/j.jcat.2010.07.032
复制
发表时间：
2010-09-30
影响因子：
7.3
通讯作者：
Libuda, J.
中科院分区：
文献类型：
--
作者：
Staudt, T.;Lykhach, Y.;Libuda, J.
CO2在二氧化铈基催化剂上的活化打开了使用CO2作为氧化剂的化学路线。为了更好地了解底层的表面反应，我们已经进行了模型研究定义良好的CeO 2-x薄膜Cu（1 1 1）在超高真空条件下。共振光电子能谱是一种高灵敏度的工具，用于监测铈的氧化态的变化，作为CO2暴露和热处理的函数。结果表明，部分再氧化CeO 2-x的CO2发生与高反应概率（i）即使在低至室温的温度下，（ii）在纯CeO 2-x在完全没有任何贵金属助催化剂，和（iii）在没有表面羟基或水。与以前对二氧化铈粉末的研究相反，研究结果清楚地表明，即使在低反应温度下，纯羟基和无金属的二氧化铈表面对CO2活化也具有高活性。(C)2010年爱思唯尔公司All rights reserved.
The activation of CO2 on ceria-based catalysts opens chemical routes to the use of CO2 as an oxidizing agent. Toward a better understanding of the underlying surface reactions, we have performed a model study on well-defined CeO2-x thin films on Cu(1 1 1) under ultra-high-vacuum conditions. Resonant photoelectron spectroscopy is used as a highly sensitive tool to monitor changes in the oxidation state of cerium as a function of CO2 exposure and thermal treatment. It is shown that partial reoxidation of CeO2-x by CO2 occurs with high reaction probabilities (i) even at temperatures as low as room temperature, (ii) on pure CeO2-x in the complete absence of any noble metal co-catalysts, and (iii) in the absence of surface hydroxyl groups or water. In contrast to previous studies on ceria powders, the findings clearly demonstrate the high activity of pure hydroxyl- and metal-free ceria surfaces for CO2 activation, even at low reaction temperatures. (C) 2010 Elsevier Inc. All rights reserved.