在CO2-到-乙烯电还原中对铜的速率决定步骤的相位切换
Yu-Cai Zhang1, Xiao-Long Zhang1, Zhi-Zheng Wu1
1Division of Nanomaterials and Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.
概括
研究人员优化了铜催化剂,以有效地将二氧化碳 (CO2) 电还原为乙烯 (C2H4). 了解不同铜表面 (100) 与111) 的速度决定步骤,提高了催化剂的性能和稳定性.
科学领域:
- 电化学 电化学 电化学
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
背景情况:
- 用电化学方法将二氧化碳 (CO2) 减少为乙烯 (C2H4) 等多碳化学物质,对于可持续的化学品生产至关重要,但在效率,速率和机制理解方面面临挑战.
- 铜 (Cu) 是二氧化碳电还原的关键催化剂,但其性能因表面结构和反应途径而异.
研究的目的:
- 阐明在不同铜表面 (Cu100和Cu111) 上的二氧化碳电还原中分离的速率决定步骤 (RDS).
- 开发和优化一个铜催化剂,以提高乙烯生产的性能.
- 在实用的电解系统中评估优化催化剂的稳定性和能效.
主要方法:
- 结合实验电催化与计算研究 (例如密度函数理论) 来研究反应机制.
- 合成和表征氧化物衍生铜催化剂,专注于控制表面面主导 (Cu(100) 与Cu(111)).
- 在电化学电池中测试了催化剂性能,测量了法拉第效率,部分电流密度和长期稳定性.
- 在膜电极组件 (MEA) 电解器中评估催化剂性能,以确定全细胞能效.
主要成果:
- 确定了C-C键的形成为Cu100上的RDS,而水对Cu111的*CO质子化是限制速度的,具有更高的能量屏障.
- 实现了Cu(100) 主导的催化剂,对C2H4表现出72%的法拉达效率,部分电流密度为359 mA cm-2和100小时以上的稳定性在500 mA cm-2.2.
- 在MEA电解器中,在70小时内表现出持续的C2H4选择性 (> 60%),达到23.4%的全电池能效.
结论:
- 控制表面结构和了解速度决定步骤对于优化铜催化剂的选择性二氧化碳电还原到乙烯至关重要.
- 开发的100) 主导催化剂为使用可再生电力从二氧化碳生产乙烯的高效和稳定的工业规模生产提供了有希望的途径.
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