Atomically Dispersed Fe1Mo1 Dual Sites for Enhanced Electrocatalytic Nitrogen Reduction

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 mgmetal -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.