Manganese-facilitated dynamic active-site generation on Ni2P with self-termination of surface reconstruction for urea oxidation at high current density

Electrochemical urea oxidation reaction (UOR) suffers from sluggish reaction kinetics due to its complex 6-electron transfer processes combined with conversion of complicated intermediates, severely retarding the overall energy conversion efficiency. Herein, manganese-doped nickel phosphide nanosheets (Mn-Ni2P) are constructed and employed for driving UOR. Comprehensive analysis deciphers that Mn doping could efficiently accelerate the surface reconstruction of Mn-Ni2P electrode, generating highly reactive NiOOH-MnOOH heterostructure with local nucleophilic and electrophilic regions. Such unique structure could accelerate the targeted adsorption and activation of C and N atoms, promoting fracture of CN bond in urea. In addition, moderate Mn doping could efficiently enhance the adsorption capacities of urea molecules and some key intermediates, and minish the energy barrier for *CO2 desorption, accelerating refreshing of the catalyst. Consequently, the Mn-Ni2P electrode exhibits excellent UOR catalytic activity, achieving an industrial-level current density of 1000 mA cm-2 at 1.46 V (vs. RHE).