Hard Lewis Acid Mo 6+ Orchestrates N‐End Urea Adsorption to Steer Highly Selective Nitrite Electrosynthesis

ABSTRACT Electrocatalytic urea oxidation reaction (UOR) offers a promising route for coupling wastewater remediation with nitrogen upgrading. However, the structural complexity of urea, containing both electron‐donating (─NH 2 ) and electron‐withdrawing (C = O) groups, leads to multiple adsorption configurations, resulting in poorly defined pathways and low selectivity toward nitrite (NO 2 ‾ ). Here, guided by Pearson's hard‐soft acid‐base theory, we develop a hard Lewis acid strategy by incorporating Mo 6+ into NiCo layered double hydroxide (NiCoMo‐LDH) to regulate interfacial electronic structure. The strong electron‐accepting nature of Mo 6+ regulates the electronic environment of Ni/Co centers, facilitating the formation and stabilization of high‐valent NiOOH/CoOOH species while creating polarized interfacial sites with enhanced affinity toward urea activation. Importantly, Mo‐induced modulation does not merely increase oxidative capability; instead, it introduces substrate‐specific adsorption regulation that favors UOR over the competing OER. This configuration regulation facilitates selective C‐N bond cleavage of the *NCONH 2 intermediate and subsequent oxidation of the generated nitrogen species toward NO 2 ‾ , achieving a Faradaic efficiency of 93.4% and a production rate of 1732.7 µmol h −1 cm −2 . This work establishes Lewis acid modulation as a strategy for controlling adsorption configurations and steering selective electrosynthesis.