Recent advances in single-atom catalysts for electrochemical nitrate reduction to ammonia

Abstract

The electrochemical nitrate reduction to ammonia (NRA) has emerged as a promising and environmentally friendly alternative to the fossil-intensive Haber-Bosch process. Single-atom catalysts (SACs) have demonstrated significant potential for NRA due to their high intrinsic activity and maximum atom utilization. Various SACs with optimized coordination configurations and enhanced adsorption properties have been reported to show excellent NH₃ selectivity, faradaic efficiency (FE), and yield rates. This review highlights recent advancements in SACs for electrochemical NRA, focusing on both noble metals (Pd, Ru, Ag, Au) and non-noble metals (Fe, Cu, Ni, Co). Key developments in the synthesis, optimization, and stabilization of SACs are discussed, with particular emphasis on the effect of supports, including metal-organic frameworks (MOFs), carbon materials, and metal oxides. This review aims to provide guidelines for the design and development of SACs in electrochemical NRA, advancing green ammonia synthesis through a comprehensive understanding of theoretical calculations and experimental findings.