电解质pH对氧化水的作用
Caiwu Liang1, Yu Katayama2, Yemin Tao1
1Department of Materials, Imperial College London, Exhibition Road, SW72AZ London, United Kingdom.
Journal of the American Chemical Society
|March 25, 2024
概括
在催化剂-电解质界面的非共价相互作用显著影响水氧化动力学. 这项研究揭示了受电解质pH影响的这些相互作用如何影响氧化电催化剂的性能.
科学领域:
- 电催化
- 表面化学
- 材料科学
背景情况:
- 设计用于氧化水的高效电催化剂对于能源转化技术至关重要.
- 了解界面现象,特别是非共价相互作用,是优化电催化剂性能的关键.
- 氧化 (IrO2) 是一个有前途的电催化剂,但它的行为在酸性和性介质之间有很大差异.
研究的目的:
- 研究中介物在两极化IrO2电解质界面上的非共价相互作用对水氧化反应 (OER) 动学的作用.
- 阐明在酸性电解质和性电解质中的IrO2OER活性之间的差异.
- 将接口特性与实验观察到的OER动力学相关联.
主要方法:
- 组合光学光谱,X射线吸收光谱 (XAS) 和表面增强红外吸收光谱 (SEIRAS) 来探测催化剂-电解质接口.
- 在酸性和性电解质中研究了IrO2的氧化演化反应 (OER) 活性.
- 对参与OER的活跃状态进行了定量分析.
主要成果:
- 活性OER物种 (Ir4.x+-*O) 在性电解质中比低覆盖度的酸性电解质具有更强的结合性.
- 在性电解质中,活性物种之间的排斥性相互作用更为明显,这是由于阴离体水化中的水量增加.
- 尽管性介质的内在结合较强,但增加的排斥性相互作用会导致覆盖范围的减弱,从而使两种电解质在相关电位下具有相似的活性状态.
结论:
- 非共价相互作用和电解质pH在调节IrO2的OER活性中起着至关重要的作用.
- 氧化中间体和远程相互作用的稳定受界面的水化结构的影响.
- 这项研究提供了OER动力学的更深层次的理解,超出了传统的计算描述符,解释了IrO2的实验观测.
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