Asymmetric configuration activating lattice oxygen via weakening d-p orbital hybridization for efficient C/N separation in urea overall electrolysis

Urea oxidation reaction (UOR) is proposed as an exemplary half-reaction in renewable energy applications because of its low thermodynamical potential. However, challenges persist due to sluggish reaction kinetics and complex by-products separation. To this end, we introduce the lattice oxygen oxidation mechanism (LOM), propelling a novel UOR route using a modified CoFe layered double hydroxide (LDH) catalyst termed CFRO-7. Theoretical calculations and in-situ characterizations highlight the activated lattice oxygen (OL) within CFRO-7 as pivotal sites for UOR, optimizing the reaction pathway and accelerating the kinetics. For the urea overall electrolysis application, the LOM route only requires a low voltage of 1.54 V to offer a high current of 100 mA cm−2 for long-term utilization (>48 h). Importantly, the by-product NCO− is significantly suppressed, while the CO2/N2 separation is efficiently achieved. This work proposed a pioneering paradigm, invoking the LOM pathway in urea electrolysis to expedite reaction dynamics and enhance product selectivity.