Modulating Electron Density of Ni‐N‐C Sites by N‐doped Ni for Industrial‐level CO2 Electroreduction in Acidic Media

Abstract

AbstractElectro‐chemically reducing CO2 in a highly acidic medium is promising for addressing the issue of carbonate accumulation. However, the hydrogen evolution reaction (HER) typically dominates the acidic CO2 reduction. Herein, we construct an efficient electro‐catalyst for CO formation based on a core‐shell structure, where nitrogen‐doped Ni nanoparticles coexist with nitrogen‐coordinated Ni single atoms. The optimal catalyst demonstrates a significantly improved CO faradaic efficiency (FE) of 96.7 % in the acidic electrolyte (pH=1) at an industrial‐scale current density of 500 mA cm−2. Notably, the optimal catalyst maintains a high FE of CO exceeding 90 % (current density=500 mA cm−2) in the electrolyte with a wide pH range from 0.67 to 14. In‐situ spectroscopic characterization and density functional theory calculations show that the local electron density of Ni‐N‐C sites is enhanced by N‐doped Ni particles, which facilitates the formation of *COOH intermediate and the adsorption of *CO. This study demonstrates the potential of a hybrid metal/Ni‐N‐C interface in boosting acidic CO2 electro‐reduction.