在催化剂上的离子膜中增强氧气运输,使用离子液添加剂
Linhao Fan1,2, Yun Wang2, Kui Jiao1
1State Key Laboratory of Engines, Tianjin University, 135 Yaguan Road, Tianjin 300350, China.
Fundamental research
|June 27, 2024
概括
将离子液添加到质子交换膜燃料电池中,可以改善氧气运输. 这提高了催化剂效率并减少了性能损失,特别是在低负载应用中.
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:
- 质子交换膜 (PEM) 燃料电池在低 (Pt) 负载下由于电催化剂上的纳米尺寸离子体薄膜中的氧 (O2) 透障碍而遭受性能损失.
- 通过离子体膜进行高效的O2传输对于开发高性能,低Pt负载的催化剂材料至关重要.
研究的目的:
- 研究添加离子液体 (ILs) 对离子体超薄亚层结构和 O2 传输的影响.
- 为了减轻阻碍O2扩散到催化剂部位的密集的离子体亚层.
主要方法:
- 用分子动力学模拟来分析具有和没有IL添加的离子体超薄亚层结构.
- 研究了ILs对 perfluorosulfonic酸链的排列以及O2溶解的自由空间的影响.
主要成果:
- 添加IL显著改变了ionomer超薄亚层结构,通过抑制硫酸链的紧密排列,而没有显著改变亚层厚度.
- ILs在超薄子层中为O2溶解创造了更大的自由空间.
- 在Pt表面的超薄子层中的O2密度增加了一个数量级,在离子体膜上的O2透流量增加了多达8倍.
结论:
- 离子液有效地减轻密集的离子体超薄亚层,增强O2运输到电催化剂部位.
- 改进的O2传输导致增强的催化效率和减少O2传输损失在低Pt负载的PEM燃料电池中.
- ILs为开发高性能燃料电池的先进低Pt加载催化剂材料提供了一个有前途的战略.
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