Zhang Hao, Raciti David, Hall Anthony Shoji
Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, USA.
Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, USA.
Nat Chem. 2025 Jul 23. doi: 10.1038/s41557-025-01859-z.
There is growing interest in the conversion of CO and CO into energy-dense multi-carbon products to help mitigate climate change, but guiding selectivity remains challenging due to competing pathways. Here we show that tuning the structure of interfacial water using highly concentrated NaClO electrolytes enhances CO electroreduction to CH. Increasing the NaClO concentration from 0.01 to 10 molal increased the CO reduction rate 18-fold, achieving a Faradaic efficiency of 91% for multi-carbon products at -1.43 V versus the normal hydrogen electrode. Temperature-dependent CO reduction, combined with surface-enhanced Raman spectroscopy, revealed that changes in the interfacial HO structure correspond to variations in the apparent activation enthalpy and entropy for the reduction of CO to CH. At higher ionic strength, increases in activation entropy were linked to disrupted hydrogen bonding and the emergence of non-hydrogen-bonded water modes, suggesting that disordered interfacial HO layers facilitate CO reduction to CH. These findings offer valuable insights into how manipulating the structure of interfacial water can enhance the reduction of CO to multi-carbon products.
将一氧化碳（CO）转化为能量密集型多碳产物以帮助缓解气候变化的研究兴趣与日俱增，但由于存在竞争途径，引导选择性仍然具有挑战性。在此，我们表明，使用高浓度次氯酸钠（NaClO）电解质调节界面水的结构可增强CO电还原为CH的过程。将NaClO浓度从0.01质量摩尔浓度提高到10质量摩尔浓度，使CO还原速率提高了18倍，在相对于标准氢电极-1.43 V的电位下，多碳产物的法拉第效率达到91%。温度依赖性CO还原与表面增强拉曼光谱相结合，揭示了界面HO结构的变化与CO还原为CH的表观活化焓和熵的变化相对应。在较高离子强度下，活化熵的增加与氢键的破坏和非氢键合水模式的出现有关，这表明无序的界面HO层促进了CO还原为CH。这些发现为如何通过操纵界面水的结构来增强CO还原为多碳产物提供了有价值的见解。
