A位缺陷对La-Sr-Co-O钙钛矿结构和催化氧化性能的影响  

Effect of A Site-deficiency on the Structure and Catalytic Oxidation Activity of the La-Sr-Co-O Perovskite

作　　者：高中楠 郭丽红[2] 赵东越 李新刚[1] GAO Zhongnan;GUO Lihong;ZHAO Dongyue;LI Xingang(Collaborative Innovation Center of Chemical Science and Engineering(Tianjin),Tianjin Key Laboratory of Applied Catalysis Science and Engineering,School of Chemical Engineering&Technology,Tianjin University,Tianjin 300354,China;School of Chemistry and Chemical Engineering,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]天津化学化工协同创新中心,天津市应用催化科学与工程重点实验室,天津大学化工学院,天津300354 [2]河南工业大学化学化工学院,郑州450001

出　　处：《高等学校化学学报》2021年第9期2869-2877,共9页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21878213);河南省科技攻关计划项目(批准号:212102310517)资助.

摘　　要：采用柠檬酸络合法制备La-Sr-Co-O钙钛矿,通过酸处理溶解Sr离子,得到了相应的A位缺陷钙钛矿.采用X射线衍射(XRD)、X射线吸收精细结构(XAFS)、电感耦合等离子体原子发射光谱(ICP-OES)、X射线光电子能谱(XPS)和拉曼光谱(Raman)等表征技术考察了A位缺陷钙钛矿的晶体结构、配位环境及表面电子结构等性质,通过CO氧化和NO氧化活性测试评价了A位缺陷钙钛矿的催化性能.结果表明,简单酸处理有选择性地改造了Sr富集区,溶解了SrCO_(3)以及大部分SrO.钙钛矿主体结构基本不变,局域结构中Sr(A位)的缺位造成Co离子以Co_(3)O_(4)形式溶出,并形成了更多的氧缺陷,有效地活化了晶格氧物种,因此其在CO氧化和NO氧化反应中均表现出更优异的低温活性.The La-Sr-Co-O perovskite was prepared by citrate acid complex method,and then the Sr ions was selectively dissolved to obtain A site-deficient perovskite.The changes of phase structure,coordination environment and electronic properties of the A site-deficient perovskite were investigated by powder X-ray diffraction(XRD),X-ray absorption fine structures(XAFS),inductively coupled plasma-optical emission spectro-scopy(ICP-OES),X-ray photoelectron spectroscopy(XPS)and Raman spectra characterization techniques.The corresponding catalytic activity was also evaluated through the CO and NO oxidation reaction.The results show that Sr-rich region is reconstructed by acid treatment through selective dissolving SrCO_(3) and SrO.The deficiency of Sr(A-site)lead to the exsolution of Co in the form of new Co_(3)O_(4) phase.More oxygen vancancies were also generated,which facilitates the generation of oxygen vacancy and activation of the lattice oxygen species.Therefore,the A site-deficient perovskite performed better CO and NO oxidation ability under low temperatures.

关 键 词：A位缺陷 钙钛矿 酸处理 一氧化碳氧化 一氧化氮氧化 

分 类 号：O643[理学—物理化学]