Shi Kaige, Janisch John, Ren Zhuanghe, Meng Zhen, Israel Deborah, Le Duy, Kaden William E, Rahman Talat S, Feng Xiaofeng
Department of Physics, University of Central Florida, Orlando, Florida 32816, United States.
Department of Chemistry, University of Central Florida, Orlando, Florida 32816, United States.
J Am Chem Soc. 2025 Jul 2;147(26):23277-23285. doi: 10.1021/jacs.5c08017. Epub 2025 Jun 18.
The electrochemical reduction of CO in acidic media has received considerable attention, as it can mitigate the carbonate formation issue. However, the available protons in acidic media can boost the hydrogen evolution reaction (HER), so alkali metal cations are generally employed to promote the CO reduction reaction (CORR) while suppressing the HER. Here we report that NH cations are more effective promoters of CO electrolysis on Au in acidic media than Na and K, achieving a 3-fold improvement in the CORR activity. The promotional effect of NH cations is mainly attributed to their enhanced electrostatic stabilization of the CO adsorption, which is the rate-limiting step for the CORR on Au. An estimation of the local pH under relevant conditions indicates that NH can mitigate the interfacial pH swing during the CORR compared to Na and K. Further studies on Au nanocatalysts of varying sizes indicate that the cation effect is independent of the catalytic sites. Our work advances the understanding of the cation effect on CORR using nonmetal cations and demonstrates a viable cation strategy to enhance CO electrolysis.
在酸性介质中，CO的电化学还原受到了广泛关注，因为它可以缓解碳酸盐形成问题。然而，酸性介质中可用的质子会促进析氢反应（HER），因此通常使用碱金属阳离子来促进CO还原反应（CORR），同时抑制HER。在此，我们报道在酸性介质中，NH阳离子在Au上对CO电解的促进作用比Na和K更有效，CORR活性提高了3倍。NH阳离子的促进作用主要归因于它们增强了对CO吸附的静电稳定作用，这是Au上CORR的速率限制步骤。相关条件下局部pH的估计表明，与Na和K相比，NH可以减轻CORR过程中的界面pH波动。对不同尺寸的Au纳米催化剂的进一步研究表明，阳离子效应与催化位点无关。我们的工作推进了对使用非金属阳离子的阳离子效应在CORR方面的理解，并展示了一种可行的阳离子策略来增强CO电解。
