Mixed-Valence Intermetallic Compounds for Urea Electrosynthesis

Efficient urea electrosynthesis relies on precisely controlling the kinetics of two parallel reduction reactions, i.e., carbon dioxide (CO₂) reduction and nitrate (NO₃^–) reduction. However, a major challenge lies in constructing stable and different active sites at the atomic scale, which are essential for synchronizing the reaction kinetics of these two reactions and facilitating C–N coupling. Herein, we introduce a mixed-valence intermetallic compound (Mv-IMC) Cu₂Sb, featuring Cu⁺–Cu²⁺ dual-sites as modular building blocks to regulate and synchronize CO₂ and NO₃^– reduction kinetics. Mechanistic studies reveal that the constructed dual-sites stabilize *CO and *NO intermediates, lower the energy barrier of C–N coupling, and significantly enhance the urea synthesis efficiency. The Cu₂Sb catalyst achieves a urea yield of 22.9 mmol h^–1 g_cat^–1 with a Faradaic efficiency of 64.9% at −0.4 V, maintaining stability over 200 h, surpassing most previously reported catalysts. This work pioneers the precise construction of multivalent active sites in Mv-IMCs, establishing a paradigm for designing high-performance electrocatalysts tailored to value-added organic synthesis.