Dynamic and Resilient Cobalt Copper Nitride and Iron Nitride Heterostructure Aided Energy Economic Urea Electrolysis in Anion Exchange Membrane Electrolyzer

ABSTRACT Urea oxidation reaction (UOR) is recognized for energy‐efficient hydrogen production, which nonetheless requires a meticulously designed electrocatalyst with active sites for intermediates adsorption and gaseous products desorption to fully exploit its advantages. Herein, we design the heterostructure consisting of cobalt copper nitride and iron nitride (Co ₃ CuN/Fe _x N _y ) as an efficient and trifunctional electrocatalyst, which requires 1.35 V _RHE , 1.55 V _RHE, and 0.23 V _RHE potentials to reach 100 mA cm ⁻² current density for UOR, oxygen evolution reaction (OER), and hydrogen evolution reaction (HER), respectively. Unlike the conventional UOR selective electrocatalyst, Co ₃ CuN/Fe _x N _y not only facilitates the UOR → OER switching but also shows self‐regulatory ability in UOR ↔ OER. The Density Functional Theory (DFT) study explained that while Co ₃ CuN promoted the adsorption of CO(NH ₂ ) ₂ and H ₂ O, Fe _x N _y facilitated CO ₂ and N ₂ desorption, resulting in accelerated UOR and HER kinetics. The electrocatalyst also demonstrated outstanding performance in a urea‐coupled AEM electrolyzer with about 20% of power saving and great electrolyzer efficiency, further highlighting its potential for industry‐relevant applications.