Pan Hui, Cheng Yingying, Kang Peng
School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, P. R. China.
Small. 2024 Dec;20(50):e2405879. doi: 10.1002/smll.202405879. Epub 2024 Sep 23.
Renewable electricity-driven CO electroreduction to value-added chemicals is a feasible approach to alleviate both environmental and energy issues. However, CO reduction reaction (CORR) systems in alkaline electrolytes are constrained by intrinsic limitations such as salt accumulation that impede further industrialization. Herein, an atomically dispersed Mn doped-nitrogen carbon (AD MnNC) catalyst is developed to electrochemically reduce CO to CO in both neutral and acidic media. Benefiting from well-dispersed MnN sites, the maximum CO Faradaic efficiency (FE) reaches ≈100% at -0.73 V versus reversible hydrogen electrode (RHE) with CO current density (J) of 20.4 mA cm in neutral 0.5 m KHCO. Due to diminished H adsorption, AD MnNC achieves a FE of 85.3% at pH 2.0, effectively suppressing the hydrogen evolution reaction (HER) in an acidic electrolyte. The mechanistic study reveals that AD MnNC accelerates the production of COOH intermediates through a proton-coupled electron transfer (PCET) pathway and thus promotes CO formation.
可再生电力驱动的CO电还原为增值化学品是缓解环境和能源问题的一种可行方法。然而，碱性电解质中的CO还原反应（CORR）系统受到诸如盐积累等内在限制的制约，这阻碍了其进一步工业化。在此，开发了一种原子分散的Mn掺杂氮碳（AD MnNC）催化剂，用于在中性和酸性介质中将CO电化学还原为CO。受益于分散良好的MnN位点，在中性0.5 m KHCO中，相对于可逆氢电极（RHE）在-0.73 V时，最大CO法拉第效率（FE）达到≈100%，CO电流密度（J）为20.4 mA cm。由于H吸附减少，AD MnNC在pH 2.0时实现了85.3%的FE，有效抑制了酸性电解质中的析氢反应（HER）。机理研究表明，AD MnNC通过质子耦合电子转移（PCET）途径加速COOH中间体的生成，从而促进CO的形成。
