特定吸附的碳酸和铜表面重建:通过时间分辨率总频生成光谱揭示的双层充电效应
Jaclyn A Rebstock1, Aishwarya Rao2, Anshuman Samanta1
1Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States.
Journal of the American Chemical Society
|August 27, 2025
概括
在CO2降解过程中,特定的离子吸附不会阻断铜电极上的CO. 相反,铜氧化和表面重建发生在毫秒的时间尺度上,影响CO脱氧和C2+选择性.
科学领域:
- 电化学
- 表面科学
- 催化剂
背景情况:
- 铜 (Cu) 电极对于选择性电化学CO2降解 (CO2R) 到C2+产品是独一无二的.
- 碳二极化过高的潜力通常归因于阻断Cu上的活性位点的离子吸附.
- 了解CO表面相互作用是优化基于Cu的CO2R催化剂的关键.
研究的目的:
- 在电化学CO2R过程中研究吸附CO在Cu电极上的表面相互作用.
- 阐明离子吸附与表面重建在CO位点阻塞中的作用.
- 测量吸附的CO的斯特克调节反应,以探测电极表面电荷和电场变化.
主要方法:
- 时间分辨率振动总频率生成 (TR-VSFG) 光谱与快速光谱收集.
- 测量可能跳跃后的CO频率变化,以解决电化学双层 (EDL) 充电.
- 从二极合和CO覆盖效应中隔离斯特拉克调节响应.
主要成果:
- 在特定离子吸附的潜在区域测量了吸附的CO对Cu的Stark调节斜率.
- 与纯的理论预测相比,观察到显著较低的Stark调整倾斜率 (4倍).
- 发现Cu电极在0.2V与RHE时至少有50%的氧化,这表明表面重建.
结论:
- 在Cu电极上的CO2R过程中,特定的离子吸附不考虑CO位点的阻塞.
- 通过在毫秒时间尺度上将Cu表面重建为类似马拉奇特的阶段来调解CO脱吸.
- 电化学双层充电动力学在控制碳对的吸附和脱离的表面过程中起着至关重要的作用.
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