Inorganic Chemicals Industry ›› 2025, Vol. 57 ›› Issue (4): 37-44.doi: 10.19964/j.issn.1006-4990.2024-0199

• Research & Development • Previous Articles     Next Articles

Hydrothermal synthesis of tin-based perovskite and study on high-temperature crystalline phase transition and surface active sites

CHEN Guanyi1(), XU Junwei2   

  1. 1. Nanchang Medical College,Nanchang 330004,China
    2. Jiangxi Provincial Academy of Sciences,Institute of Applied Chemistry,Nanchang 330096,China
  • Received:2024-04-09 Online:2025-04-10 Published:2025-04-21
  • Contact: XU Junwei E-mail:602023040002@smail.nju.edu.cn

Abstract:

To investigate the high-temperature crystalline phase transitions of tin-based perovskites and the relationship between surface active sites such as acidic and basic sites,a series of ASn(OH)6(A=Ca,Sr,Ba) precursors were prepared by hydrothermal method,and pure phase ASnO3(A=Ca,Sr,Ba) perovskite-type composite oxides were obtained by calcination under 800 ℃ under air atmosphere.The bulk and surface structure of these samples were characterized using techniques such as XRD,FTIR,Raman,XPS,and TEM.The results showed that CaSnO3 and SrSnO3 were orthorhombic phases,while BaSnO3 exhibited a cubic phase with Schottky defects.As the temperature increased from room temperature to 800 ℃,CaSnO3 and BaSnO3 did not undergo any crystalline phase transition,while SrSnO3 transformed from orthorhombic phase(Pnma) to orthorhombic phase(Imma) at high temperatures.Their surface acid-base sites were closely related to the alkalinity of A-site cations.The results showed that the stronger the alkalinity of A-site cations,the richer the basic sites,and the fewer the acidic sites.The moderate basic site was related to the concentration of oxygen vacancies.The concentration of oxygen vacancies depended on the average metal oxygen bond energy.The lower this bond energy,the more abundant oxygen vacancies and moderate basic sites.Floody-type composite oxide was an excellent oxygen ion conductor,which showed good response performance in some aerobic multi-phase catalytic reactions.The cleptication of its high temperature phase change and surface activity position was conducive to further understand their research on the research relationship in this type of reaction.

Key words: hydrothermal method, perovskite synthesis, high temperature crystalline phase transition, surface active sites, oxygen vacancy

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