π‐d Conjugated Copper Chloranilate with Distorted Cu‐O4 Site for Efficient Electrocatalytic Ammonia Production

Abstract

AbstractUnderstanding the relationship between electrocatalytic performance and local structure at the molecular level is of great significance. Herein, a bifunctional electrocatalyst CuCA (CA = chloranilate) is constructed for both nitrogen reduction reaction (NRR) and nitrate reduction reaction (NO3RR). Combined structural analyses using Rietveld refinement, extended X‐ray adsorption fine structure (EXAFS), and pair distribution function (PDF) revealed a significant distortion of the Cu‐O4 structure. Benefitting from the unique local structure, Cu‐CA shows an impressive NH3 yield rate of 286.00 ug h−1 mg−1 (FE = 18.25%, ‐0.85 V vs RHE), 3180.00 ug h−1 mg−1 (FE = 90.3%, ‐0.9 V vs RHE) for NRR and NO3RR, respectively. In contrast, the pyrazine (Pyz) decorated compound Cu‐CA‐Pyz with a less distorted Cu‐O4 structure and fewer active sites show much lower activity. Density functional theory (DFT) calculations shed light on that the distorted nature can effectively regulate the electron density distribution, which can lower the energy barrier of adsorption and activation of the intermediate species, leading to the enhanced activity. These findings may give new insight into the structural‐property relationship and open up opportunities for the exploration of efficient electrocatalysts.