Porous Cu<sub>1</sub>/TiO<sub>2–<i>x</i></sub> Catalytic Binding Pocket\nfor Near-Unity Nitrate-to-Ammonia\nConversion

Electrocatalytic nitrate reduction reaction (NO<sub>3</sub>RR)\nprovides unique opportunities to mitigate nitrate wastewater pollution\nand green ammonia production, yet the sluggish kinetics regarding\n8e<sup>–</sup> transfer and collective activation of multiple\nreactants and intermediates remain a fundamental challenge. In this\nstudy, we present a cooperative catalyst design of atomically dispersed\nCu<sub>1</sub> species embedding onto reduced anatase TiO<sub>2–<i>x</i></sub> with rich multistage pores and oxygen vacancies\n(POVs), affording the target POVs-Cu<sup>δ+</sup>-TiO<sub>2</sub> with a multisite nature. Particularly, the oxygen vacancies and\nCu<sub>1</sub> sites in proximity feature a conformational enzyme-mimicking\nnanopocket, which essentially governs the binding fit of mutative\nnitrogenate intermediates in the context of synergistic catalysis.\nThe POVs-Cu<sup>δ+</sup>-TiO<sub>2</sub> delivers a near-unity\nFaradaic efficiency (product basis 95.0%) and remarkable ammonia yield\nrate up to 1321.2 μmol h<sup>–1</sup> mg<sub>cat</sub><sup>–1</sup> at −0.7 V vs RHE. This study underscores\nthe surface topography engineering on reduced metal oxides and the\npromising synergistic effects over the NO<sub>3</sub>RR electrocatalysis,\nproviding a better alternative for nitrate wastewater pollution treatment\nand ammonia production.