Atomically Dispersed Fe₁Mo₁ Dual Sites for Enhanced Electrocatalytic Nitrogen Reduction

Abstract

The electrocatalytic nitrogen reduction reaction (eNRR) is an attractive strategy for the green and distributed production of ammonia (NH₃); however, it suffers from weak N₂ adsorption and a high energy barrier of hydrogenation. Atomically dispersed metal dual-site catalysts with an optimized electronic structure and exceptional catalytic activity are expected to be competent for knotty hydrogenation reactions including the eNRR. Inspired by the bimetallic FeMo cofactor in biological nitrogenase, herein, an atomically dispersed Fe₁Mo₁ dual site anchored in nitrogen-doped carbon is proposed to induce a favorable electronic structure and binding energy. The as-prepared electrocatalyst (FeMo-NC) presents a maximum NH₃ yield rate of 1.07 mg h^-1 mg_metal^-1 together with a Faradaic efficiency of 21.7% at -0.25 V vs RHE, outperforming many reported atomically dispersed non-noble metal electrocatalysts. Further density functional theory (DFT) calculations reveal that the Fe₁Mo₁ dual site activates *N₂ most strongly via a side-on adsorption configuration and optimizes the binding energy of eNRR intermediates, thus lowering the limiting barrier during the overall hydrogenation and promoting NH₃ generation.