关于电化学CO2降解和基于Ag的电催化剂的演变之间的竞争的机械洞察力 通过操作 拉曼光谱学
Kinran Lau1, Muhammad Adib Abdillah Mahbub1, Nini Zhang1
1Analytical Chemistry-Center for Electrochemical Sciences (CES), Faculty of Chemistry and Biochemistry, Ruhr University Bochum Universitsätsstr. 150 Bochum 44780 Germany wolfgang.schuhmann@rub.de.
Chemical science
|November 5, 2025
概括
土金属改性银催化剂揭示了在电化学二氧化碳减排 (CO2RR) 过程中演变反应 (HER) 主导的机制. 界面水重定向被确定为在高潜力时启动HER的关键因素.
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
- 频谱学是一种光谱学.
背景情况:
- 电化学 CO2 减少 (CO2RR) 到燃料和化学品需要抑制竞争的演化反应 (HER),特别是在高电流密度.
- 驱动HER在CO2RR中较高的超潜力占主导地位的机制尚不清楚,阻碍了催化剂的开发.
- 用土金属修改的白银 (Ag) 催化剂正在研究改善CO2RR性能.
研究的目的:
- 阐明 HER 在 CO2RR 期间在用土金属修饰的 Ag 催化剂上占主导地位的机制.
- 通过运行拉曼光谱学来识别CO2-CO路径中的关键中间体.
- 了解界面水在高超电位时启动 HER 的作用.
主要方法:
- 运行拉曼光谱法用于探测含有Na+的电解质中的AgMg,AgCa,AgSr和AgBa催化剂上的二氧化碳减少中间体.
- 进行了电化学测量,以将光谱特征与催化活性和反应途径相关联.
- 分析的重点是CO2RR中间体的进展和与界面水相关的光谱特征的出现.
主要成果:
- 在AgBa催化剂中,显现出CO2RR中间体 (CO2 → *COO- → *COOH → *CO) 的明显光谱证据,其阴极潜力增加.
- 在 -0.3 V 与 RHE 的负电位下,CO2RR 信号减小,与界面水升值分配的频段出现一致.
- 这种水升值带与HER电流有很强的相关性,表明它在启动HER的过程中发挥了作用,并表明了"H-down"的水配置.
结论:
- 这项研究提供了对Ag-性土金属催化剂的CO2-to-CO形成机制的直接光谱证据.
- 由电极电位驱动的有序界面水结构被认为是HER在高超电位的优势的分子起源.
- 对界面水重定向的洞察力为设计催化剂提供了一种策略,可以抑制HER并增强CO2RR.
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