在带有气体扩散阴极的微流体CO2电解器中量化质量运输限制.
Venu Gopal Agarwal1, Sophia Haussener2
1Laboratory of Renewable Energy Science and Engineering, EPFL, Station 9, Lausanne, 1015, Switzerland.
Communications chemistry
|March 5, 2024
概括
气体扩散电极 (GDE) 在二氧化碳电解中改善了二氧化碳的传输,提高了电流密度. 建模揭示了最佳条件,并建议改变电极设计,以提高二氧化碳利用率和性能.
科学领域:
- 电化学 电化学 电化学
- 化学工程是化学工程的重要组成部分.
- 材料科学 材料科学 材料科学
背景情况:
- 传统的二氧化碳电解使用平面浸泡电极,限制了二氧化碳运输到催化剂.
- 气体扩散电极 (GDE) 为增强的电化学反应提供了改进的质量传输.
研究的目的:
- 开发和验证使用GDE的微流体CO2电解电极的2D模型.
- 调查运行参数和电极材料对二氧化碳转化为二氧化碳的影响.
- 确定优化催化剂利用和CO部分电流密度 (PCD) 的策略.
主要方法:
- 为GDE阴极开发一个二维计算模型.
- 对模型与实验数据的验证.
- 模拟CO2电解在不同的条件下 (例如,流速,潜力).
主要成果:
- 该模型预测完全淹没的催化剂层的CO部分电流密度 (PCD) 峰值为75mA cm-2在-1.3V与RHE下.
- 在催化剂表面附近的二氧化碳可用性限制了更高电位的PCD.
- 电解质和二氧化碳的流量率显著影响PCD,PCD和二氧化碳转换效率之间存在权衡.
结论:
- GDE 增强了二氧化碳的传输,增加了二氧化碳电解中的电流密度.
- 催化剂层的很大一部分在当前的设计中仍未得到充分利用.
- 优化电极多孔性和采用异型层可以改善质量传输和CO PCD.
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