基于机制的分解:通过控制质子交换膜水电解剂中的电压保持模式来理解降解
Ai-Lin Chan1, Steven C Hayden2, Steven P Harvey2
1Chemical and Material Sciences Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States.
概括
质子交换膜 (PEM) 水电解稳定性受到低催化剂负载的挑战. 与潜在循环相比,恒定电压保持提高了催化剂的耐用性,而潜在循环通过破坏催化剂层和离子体而降低了性能.
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
- 催化剂是一种催化剂.
背景情况:
- 质子交换膜 (PEM) 水电解对于绿色的生产至关重要.
- 在PEM电解器中,低催化剂负载会导致性能不稳定性和随着时间的推移而降解.
- 了解退化机制对于提高长期运行稳定性至关重要.
研究的目的:
- 调查不同压力条件对PEM水电解器降解机制和电压损失率的影响.
- 为了比较潜在循环与恒定电压对催化剂稳定性和性能的影响.
- 阐明 (Ir) 迁移和催化剂层 (CL) 完整性在PEM电解器耐用性中的作用.
主要方法:
- 对膜电极组件应用不同的应力测试 (电位循环和恒定2V保持).
- 对氧化结晶,离子体降解和催化剂层稀释的分析.
- 评估动力损失率,包括Tafel斜率,极化动力学和电荷转移阻力.
主要成果:
- 潜在循环诱导了显著的氧化结晶,离子体降解和CL稀释,导致更高的动力损失.
- 恒定的2V保持导致更均的带形成,保持催化活性和提高动力耐用性.
- 潜在的循环导致断开的聚合物迁移,电荷转移阻力增加,以及大量的离子体损伤,减少活性点.
结论:
- 在PEM水电解中,负载保持与潜在循环之间存在不同的降解途径.
- 与潜在循环相比,恒定电压保持可以提高动力耐用性和稳定性.
- 基于催化剂 - 离子体相互作用的优化运行策略是PEM电解器长期性能的关键,特别是在间歇性能源中.
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