高等学校化学学报 ›› 2021, Vol. 42 ›› Issue (9): 2869.doi: 10.7503/cjcu20210311

• 物理化学 • 上一篇    下一篇

A位缺陷对La-Sr-Co-O钙钛矿结构和催化氧化性能的影响

高中楠1, 郭丽红2(), 赵东越1, 李新刚1()   

  1. 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
  • 收稿日期:2021-05-04 出版日期:2021-09-10 发布日期:2021-09-08
  • 通讯作者: 郭丽红,李新刚 E-mail:lhguo@haut.edu.cn;xingang_li@tju.edu.cn
  • 基金资助:
    国家自然科学基金(21878213);河南省科技攻关计划项目(212102310517)

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

GAO Zhongnan1, GUO Lihong2(), ZHAO Dongyue1, LI Xingang1()   

  1. 1.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
    2.School of Chemistry and Chemical Engineering,Henan University of Technology,Zhengzhou 450001,China
  • Received:2021-05-04 Online:2021-09-10 Published:2021-09-08
  • Contact: GUO Lihong,LI Xingang E-mail:lhguo@haut.edu.cn;xingang_li@tju.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21878213);the Scientific and Technological Project of Henan Province, China(212102310517)

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SrCO3 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Co3O4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.

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

Abstract:

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 SrCO3 and SrO. The deficiency of Sr(A-site) lead to the exsolution of Co in the form of new Co3O4 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.

Key words: A-deficiency, Perovskite, Acid treatment, CO oxidation, NO oxidation

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