Mechanism of key intermediates regulation in electrocatalytic nitrate-to-ammonia conversion driven by polarized electric field

Abstract

Ammonia (NH₃) plays a crucial role in agricultural production and chemical industry, and it is predicted to be an ideal future energy carrier. The traditional Haber-Bosch process, used for ammonia synthesis, operates under high temperatures and pressures, leading to significant energy consumption and carbon dioxide emissions. In contrast, the electrocatalytic nitrate reduction reaction (NO3RR) offers a promising and sustainable pathway for valuable NH₃ production. However, challenges on the rational regulation of intermediates remain, the sluggish reaction kinetics and poor selectivity leads to low NH₃ yield, further restricted cascade reaction towards industrial implementation. Notably, polarized electric fields can modulate the charge distribution at catalyst active sites, enhancing catalytic efficiency, thus has emerged as one of the most effective strategies for addressing these challenges. Therefore, this review begins with a practical perspective, exploring the mechanisms and challenges in NO3RR, and highlighting advancements in polarized electric field-assisted NO3RR, including the utilization of single-atom catalysts, defect engineering, and heterostructures. This review also analyzes the mechanisms by which polarized electric fields regulate reaction pathways and construct cascade reactions for intermediate products control. Furthermore, emphasized how theoretical calculations predict reaction pathways, evaluate energy barriers, and provide electronic structure insights that guide the design and optimization of catalysts. Finally, future development directions and prospects for NO3RR under the regulation of polarized electric fields are discussed. This review underscores the value and versatility of polarized electric fields in NO3RR, paving the way for significant progress in energy and environmental catalysis.