Recent advances in the catalysts for electroreduction of nitrate to nitrogen-containing chemicals: From reaction mechanism/pathway aspect

Abstract

The electrocatalytic nitrate reduction reaction (NO₃RR) has emerged as a sustainable "win-win" strategy for mitigating environmental nitrate (NO₃^-) pollution while simultaneously synthesizing high-value-added nitrogenous chemicals under ambient conditions. This review provides a comprehensive analysis of recent advancements in NO₃RR catalysts, specifically through the lens of reaction mechanism and pathway. We first discuss the pivotal roles of advanced in situ characterization techniques and multi-scale theoretical simulations in capturing reactive intermediates and elucidating the dynamic structural evolution of catalysts at the electrode-electrolyte interface. Regarding ammonia (NH₃) synthesis, we emphasize strategies for enhancing nitrate adsorption, balancing activation kinetics at multifunctional sites, and directing the reaction pathway to suppress the competitive hydrogen evolution reaction. For urea production, we examine the co-reduction of nitrate and carbon dioxide (CO₂), focusing on the design of catalytic sites that optimize nitrogenous and carbonaceous intermediate adsorption and lower the energy barriers for C-N coupling. Thereafter, the synthesis of high-value chemicals such as amino acids, amides, and nitriles via the "oxime-intermediated" pathway is explored. Furthermore, the integration of data-driven paradigms, including high-throughput screening and machine learning, is highlighted as an emerging frontier for accelerating catalyst screening and uncovering non-intuitive structure-activity relationships. Finally, this review proposes potential directions on addressing critical challenges—such as selectivity-activity trade-offs, long-term stability, and system-level industrial integration—to provide actionable guidance for the rational design for high performance NO₃RR electrocatalysts.