Intermediate‐Mediated Selectivity in Electrocatalytic Nitrate Reduction for Nitrogen Product Synthesis

ABSTRACT Electrocatalytic nitrate (NO 3 − ) reduction reaction (eNO 3 RR) has emerged as a promising strategy for waste NO 3 − valorization, offering opportunities for environmental remediation. However, its complex proton‐coupled electron transfer processes involve multiple competing pathways, in which the fate of key intermediates governs reaction activity and product selectivity. In this review, we provide an intermediate‐centered perspective on eNO 3 RR, covering the reaction pathways from NO 3 − activation to the selective synthesis of NH 3 , N 2 , and NH 2 OH. We then summarize current techniques for probing N‐containing intermediates and active hydrogen (*H). On this basis, we discuss how catalyst design and microenvironment engineering regulate key processes in eNO 3 RR, including intermediate adsorption, retention and desorption, N─O bond cleavage, hydrogenation, and N─N coupling. We also examine the emerging role of data‐driven approaches in optimizing eNO 3 RR systems. Drawing these discussions together, we distill principles for selective product synthesis. Finally, we discuss remaining challenges in achieving a deeper mechanistic understanding, regulating the interfacial microenvironment, and applying eNO 3 RR to real wastewater.