在纳米孔状电催化剂中通过减少氧气抑制进化
Ellen E Benn1, Bernard Gaskey1, Jonah D Erlebacher1
1Department of Materials Science and Engineering, Johns Hopkins University , Baltimore, Maryland 21218, United States.
Journal of the American Chemical Society
|February 18, 2017
概括
研究人员通过控制对纳米孔-电极的质子和反应物运输来抑制电还原过程中的进化反应 (HER). 这种策略增强了氧降解反应 (ORR) 的选择性和活性.
科学领域:
- 电化学
- 材料科学
- 化学工程
背景情况:
- 演化反应 (HER) 经常与所需的电还原反应竞争.
- 过高的潜力会加剧竞争,降低效率.
- 控制反应物运输对于选择性电催化是至关重要的.
研究的目的:
- 研究对电催化剂的质子和反应物运输动力学.
- 了解运输和催化性能之间的关系.
- 开发抑制HER和增强氧降低反应 (ORR) 的策略.
主要方法:
- 在酸性电解质中的质子扩散限制条件下研究ORR.
- 使用非合的纳米孔 (np-NiPt) 电极.
- 将缓冲和非缓冲溶液进行比较,以探测界面pH效应.
主要成果:
- 完全抑制HER即使在高超电位 (-400mV与RHE).
- 证明缓冲与非缓冲溶液改变了ORR机制.
- 与表面pH的短暂变化相关的反应选择性.
结论:
- 在高超电位下控制反应物运输提供了一个可通用的策略.
- 这种方法可以显著提高电还原反应的活性和选择性.
- 界面pH在决定ORR选择性方面起着至关重要的作用.
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