Synergistic effects in FeP4-NPC-CP Nanocomposites electrocatalysts for Boosted nitrate reduction to ammonia

Abstract

An electrocatalytic reduction of NO₃⁻ to NH₃ operates as a promising methodology both for sustainable nitrogen cycle management and ammonia industrial production. Herein, an advanced NO₃⁻RR electrocatalyst based on iron phosphide-nitrogen-phosphorus doped carbon (FeP₄-NPC) nanoparticle is prepared, which shows exceptional performance for nitrate reduction reactions, exhibiting an ammonia yield of 0.500 mmol h⁻¹mg⁻¹_cat. and Faradaic efficiency of 86.18 % at an optimized potential of −1.655 V vs. SCE under neutral conditions due to improved charge transfer capabilities and active site availability. The electrochemical tests also demonstrate both superior longevity and recyclability because the catalyst maintains its current density output as well as solution integrity across numerous operational cycles without deterioration. Moreover, based on detailed mechanistic studies by different characterizations and theoretical calculations, the super hydrophilic and electrophilicity (Fe) properties of FeP₄-NPC heterostructure interface synergistically promote to build better interfacial charge transfer and reactivity and contribute to the easy and fast accessibility of reactant species, which in turn help to reduce energy barrier of rate-determining step (*NO→*NHO) significantly and to inhibit the side reaction of hydrogen evolution. This investigation offers a deep understanding of the design of promising electrocatalysts for electrochemical ammonia production.