Time-resolved in situ UV/vis spectroscopy for analyzing the dynamics of surface and bulk redox processes in materials used as oxygen storage capacitors
Time-resolved in situ UV/vis spectroscopy for analyzing the dynamics of surface and bulk redox processes in materials used as oxygen storage capacitors
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DOI：
10.1016/j.cattod.2010.10.015
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发表时间：
2011-04-30
期刊：
影响因子：
5.3
通讯作者：
Shinjoh, Hirofumi
中科院分区：
文献类型：
--
作者：
Kondratenko, Evgenii V.;Sakamoto, Yoshiyuki;Shinjoh, Hirofumi
采用时间分辨紫外/可见-漫反射（UV/维斯）光谱法对无Pt和含Pt的CeO（2）-ZrO（2）储氧电容器的还原和再氧化动力学进行了原位监测。该方法也可用于测定氧气释放速度。将光谱催化剂表征与瞬态反应分析（CO（H（2））和O（2）的交替进料）相结合，使我们能够确定决定二氧化铈的表面和本体氧化还原过程的因素。Pt的存在大大增加了CeO（2）-ZrO（2）中晶格氧的迁移率和氧释放反应的可用性，而强烈聚合的CeO（x）物种（ZrO（2）在CeO（2）中的非均匀分布）的存在降低了晶格氧的迁移率。本原位UV/vis-DR分析的结果支持以前的非直接得出的结论。(C)2010 Elsevier B. V.保留所有权利。
Time-resolved UV/vis-DR (diffuse reflectance UV/vis) spectroscopy was used to in situ monitor the dynamics of reduction and reoxidation of Pt-free and Pt-containing CeO(2)-ZrO(2) used as oxygen storage capacitors. This method can be also applied for measuring the speed of oxygen release. Combining the spectroscopic catalyst characterization with transient reaction analysis (alternating feeding of CO(H(2)) and O(2)) enabled us to identify factors determining surface and bulk redox processes of ceria. The presence of Pt increased strongly the mobility and availability of lattice oxygen in CeO(2)-ZrO(2) for oxygen release reactions, while the presence of strongly polymerized CeO(x) species (non-homogeneous distribution of ZrO(2) in CeO(2)) decreased the mobility of lattice oxygen. The results of the present in situ UV/vis-DR analysis support previous non-directly derived conclusions. (C) 2010 Elsevier B.V. All rights reserved.