大量独立的表面氧化物组成控制了高合金的电化学性能
Matthias Kogler1,2, Matteo Olgiati1,2, Markus Ostermann2
1Institute of Applied Physics, Vienna University of Technology 1040 Vienna Austria markus.valtiner@tuwien.ac.at christian.pichler@cest.at.
Journal of materials chemistry. A
|August 29, 2024
概括
多元元素合金的表面成分与其体积有很大不同,这影响了水分裂的电催化性能. 了解这种表面氧化物是优化催化剂的关键,而高设计没有额外的好处.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 表面科学是一门学科.
背景情况:
- 多元素和高合金为先进的催化应用提供可调节的组合.
- 这些合金的反应性表面组成往往不同于它们的大体,极大地影响了电催化活性.
- 了解表面氧化物演变对于控制和提高催化剂性能至关重要.
研究的目的:
- 在各种pH条件下研究基于Ni的多金属合金 (含Mn,Fe,Co,Cr) 的表面氧化物组成.
- 为了将表面氧化物组成与氧化物演化反应 (OER) 的电催化活性相关联.
- 将高合金的OER性能与二进制和三进制对应物进行比较.
主要方法:
- 低能离子散射光谱 (LEIS) 用于亚纳米深度解析的表面氧化物分析.
- 进行了电化学测试,以评估氧化演化反应 (OER) 的催化活性.
- 合金组合物被系统地变化,以研究合金元素的影响.
主要成果:
- 在OER条件下,Ni基合金的表面氧化物成分与散装成分有显著的偏差.
- 观察到OER的电催化活性,显示出对反应环境 (pH) 的强烈依赖.
- 对于OER,高合金与更简单的二进制或三进制合金相比没有提供显著的性能优势.
结论:
- 表面成分分析对于理解多元元素合金的电催化作用至关重要.
- 形成的特定表面氧化物决定了催化性能,催化性能对工作条件敏感.
- 对于OER催化,复杂的高化合物可能无法超过优化的简单合金.
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