洞察光酸功能化的基基介质质子交换膜燃料电池中的质子转移
Yuhua Zhou1, Jing Yang, Haibin Su
1School of Materials Science and Engineering, Nanyang Technological University , 50 Nanyang Avenue, 639798 Singapore.
Journal of the American Chemical Society
|March 18, 2014
概括
我们开发了一种用于燃料电池的新型质子交换膜 (PEM),使用酸 (HPW) 和中孔. DFT计算揭示了质子转移机制,解释了HPW-meso-silica膜的高导电性.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 计算化学计算化学
背景情况:
- 质子交换膜 (PEM) 是燃料电池中的关键组件,可实现质子运输.
- 开发高效和稳定的PEM对于推进燃料电池技术至关重要.
- 无机材料在稳定性和导电性方面具有潜在的优势.
研究的目的:
- 开发一种用于燃料电池的新型质子交换膜 (PEM),利用无机酸 (HPW) 和半孔.
- 通过密度函数理论 (DFT) 研究HPW-meso-silica PEM开发中的质子迁移能量和跳跃机制.
- 为了将计算发现与实验性质子导电性测量相关联.
主要方法:
- 合成了一种新的HPW-meso-silica复合材料用于PEM应用.
- 电化学阻抗光谱 (EIS) 用于测量质子导电性和激活能量.
- 密度函数理论 (DFT) 计算使用通用梯度近似 (GGA) 来建模质子转移路径和能量.
主要成果:
- 在90°C和100%相对湿度 (RH) 时,HPW-meso-silica PEM的质子导电率为0.11 S cm(-1),低激活能量为~14 kJ mol(-1).
- DFT计算确定了膜内的分子内和分子间的质子转移通路.
- 发现分子内质子转移途径是限制速率的步骤,确定了总体质子导电性,并解释了在67重%HPW以上的导电性平原.
结论:
- 开发的HPW-meso-silica PEM证明了燃料电池应用的前景良好的质子导电性.
- DFT计算提供了对质子转移机制的关键见解,突出了HPW内部分子内转移的作用.
- 这些发现表明,优化HPW加载和排列是提高PEM性能的关键,而纯表面的质子导电性较差.
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