在性介质中对Pt单晶电极的氧化反应的子效应
Linfan Shen1, Akansha Goyal1, Xiaoting Chen1,2
1Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands.
The journal of physical chemistry letters
|March 7, 2024
概括
在氧化反应 (HOR) 中,电极上的阴离子效应取决于电极结构和pH值. 虽然离子在低度的步骤上促进HOR,但在更高度和度下抑制它,特别是在露台上.
科学领域:
- 电化学 电化学 电化学
- 表面科学是一门学科.
- 催化剂是一种催化剂.
背景情况:
- 氧化反应 (HOR) 对燃料电池至关重要.
- 了解性介质中电极上的阴离子效应是提高HOR效率的关键.
- 现有的研究表明,关于子影响的机制是相互矛盾的.
研究的目的:
- 为了阐明电极上的阴离子辅助HOR对结构敏感的机制.
- 调查阴离子性质,度和pH值对HOR活性的影响.
- 为了区分梯田与台阶站点上的阴离子作用.
主要方法:
- 在具有不同表面结构的电极上进行电化学测量 (111) 露台和 (110) 步骤).
- 阴离子类型,度和电解质pH的系统变化.
- 分析吸附和HOR动力学的分析.
主要成果:
- 在 (111) 露台站点上的HOR活动是独立于阴离子类型和度的.
- 在 (110) 步位上,在低度/轻度下促进HOR,但在高度/高度下抑制它.
- 吸附的氧化物 (OHad) 物种抑制HOR,对露台和台阶站点有不同的影响.
结论:
- 阴离子对HOR的影响对结构高度敏感,在白金露台和台阶之间有所不同.
- HOR机制从低超电位的主要阶段介导转变为在扩散有限条件下的梯间介导.
- 电极结构和电解质pH值是控制性HOR中的阴离子效应的关键因素.
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