CeO_2及Ce_(0.5)Zr_(0.5)O_2固态溶液的现场拉曼光谱比较  

In Situ Raman Spectroscopic Study of CeO 2 and Ce 0.5 Zr 0.5 O 2 Solid Solution

作　　者：缪建英[1] 蔡俊修[1] 

机构地区：[1]厦门大学化学系催化教研室固体表面物理化学国家重点实验室

出　　处：《厦门大学学报（自然科学版）》1999年第2期235-241,共7页Journal of Xiamen University：Natural Science

基　　金：福建省自然科学基金

摘　　要：控制合成条件以湿化学法制备超细颗粒ＣｅＯ２和Ｃｅ０．５Ｚｒ０．５Ｏ２固溶体．Ｘ射线粉末衍射证实两者皆为立方相．在氧化、还原气氛５０℃到６５０℃条件下分别对样品进行原位拉曼光谱研究．结果发现除４４０～４７０ｃｍ－１出现面心立方晶格Ｆ２ｇ拉曼活性模式对应的强拉曼谱峰外，２２０～２８０（２９０～３２０）、４００～４１０和５６０～６００（５７０～６２０）、７８０～８４０（７７０～７９０）及１１５０～１１８０（１１６０～１１９０）ｃｍ－１分别出现弱拉曼谱峰．这些弱拉曼谱峰由不同原因引起的晶体结构改变造成．ＣｅＯ２和Ｃｅ０．５Ｚｒ０．５Ｏ２固溶体的各拉曼弱峰变化情况不同．弱拉曼谱峰的存在及变化趋势揭示了ＣｅＯ２和固溶体的结构特征，同时也反映了Ｃｅ０．５Ｚｒ０．CeO 2 and Ce 0.5 Zr 0.5 O 2 solid solution were prepared by wet chemical preparation method. Their crystal structures are face centered cubic(fluoritetype), verified by powder X ray diffraction. In situ Raman spectra of the catalysts from 50 to 650℃ in oxygen and hydrogen atmosphere show the 440～470 cm -1 strong Raman peaks due to the F 2g Raman active mode of fluorite structure materials. 220～280(290～320), 400～410 and 560～600(570～620), 780～840(770～790) and 1 150～1 180(1 160～1 190) cm -1 weak Raman peaks are also present. These weak Raman peaks originated from the disorder of crystal structures with different reasons. The Raman peaks of CeO 2 and Ce 0.5 Zr 0.5 O 2 solid solution have different changes with the alteration of environmental conditions. Characterization of CeO 2 and Ce 0.5 Zr 0.5 O 2 solid solution can be given from the weak Raman peaks. These peaks also reveal the structural reasons of higher catalytic reactivity and larger oxygen storage capacity of the Ce 0.5 Zr 0.5 O 2 solid solution.

关 键 词：拉曼光谱 铈-锆-氧固溶体 固溶体 氧化铈 催化剂 

分 类 号：O643.36[理学—物理化学]