Introducing ionic mediators to construct peak-splitting manganese oxide structures for efficient oxygen reduction reactions  

作　　者：Haoliang Ma Xiong Li Mengmeng Tian Lanlan Li Xiaofei Yu Xinghua Zhang Zunming Lu Xiaojing Yang 

机构地区：[1]School of Materials Science and Engineering,Tianjin Key Laboratory of Materials Laminating Fabrication and Interface Control Technology,Hebei University of Technology,Tianjin 300130,China [2]School of Artificial Intelligence and Information Technology,Nanjing University of Chinese Medicine,Nanjing 210023,China

出　　处：《Journal of Materials Science & Technology》2024年第34期139-148,共10页材料科学技术(英文版)

基　　金：supported by the Hebei Province Higher Edu-cation Scientific Research Project(No.JZX2024029)。

摘　　要：Manganese oxides have received extensive attention in Oxygen Reduction Reaction(ORR)research.How-ever,the poor electrical conductivity and oxygen adsorption capacity of manganese oxides limit their development,so it is necessary to prepare catalysts with highly active surfaces.We propose a method to introduce an ionically conductive medium and induce structural distortion via thermodynamics,re-sulting in novel peak-splitting highly active structures for enhanced oxygen reduction activity.With the aid of refined structural analysis,High-angle annular dark-field(HAADF-STEM)imaging,and theoretical calculations,it is elucidated that this peak-splitting structure results from thermodynamically induced structural distortions and atomic displacements.The introduction of the ionically conductive medium promotes the formation of Ag-O-Mn conductive bond bridges,which regulate the energy level matching of manganese oxides and oxygen intermediates.The thermodynamically induced structural distortion ex-poses new atomic planes in the material,and the creation of this highly active surface is accompanied by a redistribution of surface charges,which modulates the adsorption of manganese active sites with oxy-gen intermediates and greatly enhances the oxygen reduction activity.Specifically,this Ag-OMS-2 with a novel split structure exhibits excellent activity at 0.836 V,superior to Pt/C kinetics and good stability.The preparation of such highly active structures is instructive for the development of manganese oxides.

关 键 词：Fuel cells ELECTROCHEMISTRY MANGANESE Structural distortion Ionically conductive medium 

分 类 号：O64[理学—物理化学]