Facilitating reactant accessibility to heterometallic phosphide with superhydrophilic interfaces for efficient electrochemical production of ammonia and lactic acid

Electrocatalytic ammonia production requires high-performance catalysts for high-efficiency cathodic nitrate reduction reaction (NO3RR) and rapid oxidation reaction. Herein, an advanced NO3RR electrocatalyst based on bimetallic Co-Fe phosphide (Co-Fe-P) hollow nanocubes is prepared, which exhibits a high NH3 yield rate of 21.11 mg h−1 mgcat.−1 with Faradaic efficiency of 98.9 % under neutral conditions. Furthermore, continuous ammonia (>94.2 % selectivity) and lactic acid production can be obtained at lower applied voltages by using a two-electrode system integrating NO3RR with glycerol oxidation reaction. Based on detailed mechanistic investigations by in situ characterizations and theoretical calculations, the superhydrophilic property and dual-function centers of nucleophilicity (Co) and electrophilicity (Fe) of the FeP/CoP heterostructure interface synergistically contribute to the rapid accessibility of reactant species, reducing the energy barrier of rate-determining step (*NO→*NHO) and inhibiting the competing hydrogen evolution side reaction. This study provides deep insight into the design of high-efficiency electrocatalysts for nitrogen-neutral cycles.