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硬X射线光电子光谱检测氧气进化反应过程中的Fe分离

Filippo Longo^1,2, Pedro Javier Lloreda-Jurado³, Jorge Gil-Rostra³

¹Chemical Energy Carriers and Vehicle Systems Laboratory, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.

ACS applied materials & interfaces

|October 17, 2024

概括

铁 (NiFe) 电催化剂对水分解具有很高的活性. 这项研究表明,受催化剂多孔性的影响,铁分离到表面,形成不活性相,影响整体性能.

科学领域:

电化学电化学电化学
材料科学材料科学材料科学
表面科学是一门学科.

背景情况:

-铁 (NiFe) 电催化剂在水分裂中对氧演化反应 (OER) 非常活跃.
了解Ni-Fe的相互作用和表面现象对于设计高效的分水电极至关重要.
电化学反应诱导复杂的表面变化,如氧化物形成和物种分离,阻碍了合理的设计.

研究的目的:

开发和应用一种使用XPS/HAXPES量化化学深度分析的方法.
在OER期间研究具有不同孔径的NiFe电极的表面重建.
阐明孔隙在铁分离中的作用及其对电催化剂性能的影响.

主要方法:

使用X射线光电子谱学 (XPS) 和硬X射线光电子谱学 (HAXPES) 进行定量化学深度分析.
将开发的方法应用于具有明显孔隙性的两个NiFe电极.
在电化学氧气演化反应期间表面重建的现场分析.

主要成果:

在环境条件下,铁 (Fe) 分离到表面,形成一个不活的FeO阶段.
催化剂的多孔性显著影响Fe分离过程和电极性能.
在纳米结构样本中,较高的多孔性会导致Fe扩散的增加和活性NiFe-oxyhydroxide相的抑制.

结论:

多元素系统的表面化学是动态的,取决于应用的电位,电解质和散装性质.
孔隙性是NiFe电催化剂设计的关键因素,影响Fe表面分离和OER活性.
HAXPES提供了关键的洞察力,了解影响地表行为的地下特性.

关键词:

Fe 表面分离的表面分离哈克斯佩斯 (HAXPES) 是一个尼菲-氧化氧化物纳米结构薄膜催化剂非破坏性的深度化学配置文件.氧气进化反应反应氧气进化反应

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