Amorphization Engineering Coupled with Anion Leaching Boosts Precatalyst Reconstruction for Enhanced Urea Oxidation.

Ni-based materials have emerged as a class of promising precatalysts for the urea oxidation reaction (UOR), yet inherent structure-related reconstruction behavior of the precatalyst and correlation with electrocatalytic activity are not well-understood, severely hindering rational design of advanced catalysts. Herein, a new type of precatalyst, amorphous Mn-incorporated NiWO4 (a-MnNi-WO4), is constructed via rapid co-precipitation followed by mild heat treatment, and proposed for expediting the UOR. Intriguingly, loose and flexible amorphous phase engineering and leachable WO4 2- incorporation can collaboratively prompt a-MnNi-WO4 to access fast and complete self-reconstruction during UOR, thus generating porous, oxygen-vacancy-enriched, and low-crystalline Mn-doped NiOOH with optimized electronic structure for prompting urea adsorption and the rate-determining step of *COO desorption. Impressively, the a-MnNi-WO4 can deliver admirable UOR behavior and considerably outperform the crystalline counterpart as well as the amorphous ones without WO4 2- or Mn species incorporation, favorably presenting the state-of-the-art level. This work elucidates an in-depth understanding of the reconstruction ability of the precatalyst for promoting the UOR, and material design principle for achieving fast and deep self-reconstruction via amorphization engineering and sacrificial anion etching is expected to extend to construct other advanced electrocatalytic systems.