Electrochemical reduction of nitrate to Ammonia: Recent progress and future directions

Ammonia (NH3) is essential for global food production as a key agricultural fertilizer and is increasingly recognized as a renewable energy carrier. The electrochemical nitrate reduction (eNO3RR) method stands out as a promising alternative to the traditional, energy-intensive and CO2-emitting Haber-Bosch process, capable of converting residual NO3 - pollutants in water systems into valuable NH3 under ambient conditions. Advancing this process toward commercialization relies on the development of electrocatalysts that are highly active, durable, and cost-effective. This article reviews recent progress in electrocatalyst design aimed at improving the efficiency and selectivity of the NO3 - to NH3 conversion. Through an exploration of innovative strategies, including doping, alloying, defect engineering, hybridization and single/dual-atom catalysts, this review details how these methods have markedly enhanced catalyst performance, offering avenues to surmount the challenges posed by traditional pure material-based electrocatalysts. Furthermore, the potential for scaling up these technologies for industrial applications is explored. The objective is to provide a comprehensive overview that not only addresses the scientific and technical challenges but also suggests future directions in the development of sustainable and efficient ammonia synthesis technologies, contributing to global efforts in sustainable energy and agricultural practices.