Spin‐Selective Anti‐Perovskite Enables Breakthrough Nitrate‐to‐Ammonia Electrocatalysis

ABSTRACT Electrochemical nitrate reduction to ammonia offers environmental and energy benefits, but progress is hindered by sluggish multistep proton‐coupled electron transfers and competing side reactions. Here, we introduce an antiperovskite CuNCo 3 catalyst featuring a 3 d –3 d interaction framework. This framework stabilizes spin‐selective Co sites even upon surface Co‐N bond cleavage and drives asymmetric nitrate consumption. CuNCo 3 achieves 100% Faradaic efficiency and an NH 3 production rate of 124.6 mg mg cat −1 h −1 at −0.4 V vs. RHE. Operando XAS, XES, and ATR‐FTIR directly link the evolution of spin‐selective Co sites with specific NO 3 RR intermediates, revealing that spin‐selective Co sites lower hydrogenation barriers and accelerate key steps. These results demonstrate that spin‐selective anti‐perovskite frameworks provide a robust, earth‐abundant platform for high‐performance nitrate‐to‐ammonia electrocatalysts.