通过调整微环境水活动的微观环境,提高Pt的氧气减少[111]
Yujun Xu1, Lulu Zhang1, Wei Chen1
1Hefei National Research Center for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, China.
ACS applied materials & interfaces
|January 16, 2024
概括
较高的干燥温度通过影响离子体湿而降低聚合物电解质膜燃料电池性能. 内在的氧降解反应活性高于明显的,这表明改进了膜电极组装准备方法.
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
- 化学工程是化学工程的重要组成部分.
背景情况:
- 质子交换离子体对聚合物电解质膜燃料电池 (PEMFCs) 至关重要,可实现质子导电和结合纳米催化剂.
- 膜电极组件 (MEAs) 内的微环境,特别是在三相接口,显著影响电极动力学,如氧减少反应 (ORR).
研究的目的:
- 为了研究离子体浸湿条件对Pt111离子体接口的氧降解反应 (ORR) 的影响.
- 了解干燥温度如何影响离子体的行为和内在ORR活动.
- 为优化MEA准备提供见解,以提高ORR性能.
主要方法:
- 使用一个模型系统的Pt(111) 下载X 离子体接口 (X = Nafion,Aciplex,D72).
- 研究了干燥温度对硫酸盐吸附和ORR动力学的影响.
- 分析了硫酸盐吸附和PTFE骨架在Pt活性部位上的阻断作用.
主要成果:
- 较高的干燥温度降低了硫酸盐吸附开始潜力和明显的ORR电流.
- 吸附基 (OHad) 形成的电流波转向正面并减少.
- 在考虑阻断效应后,发现ORR内在活动高于明显活动.
- 由离子体/PTFE诱导的界面上的水活动减少解释了观察到的混合潜力效应.
结论:
- 干燥温度极大地影响PEMFC中的离子体湿和ORR性能.
- 内在ORR活动高于测量值,突出显示了对表面阻塞效应进行校正的重要性.
- 通过控制离子体/PTFE相互作用和水活性来优化MEA制备可以提高ORR性能.
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