Porous Cu1/TiO2–x Catalytic Binding Pocket for Near-Unity Nitrate-to-Ammonia Conversion

Electrocatalytic nitrate reduction reaction (NO3RR) provides unique opportunities to mitigate nitrate wastewater pollution and green ammonia production, yet the sluggish kinetics regarding 8e– transfer and collective activation of multiple reactants and intermediates remain a fundamental challenge. In this study, we present a cooperative catalyst design of atomically dispersed Cu1 species embedding onto reduced anatase TiO2–x with rich multistage pores and oxygen vacancies (POVs), affording the target POVs-Cuδ+-TiO2 with a multisite nature. Particularly, the oxygen vacancies and Cu1 sites in proximity feature a conformational enzyme-mimicking nanopocket, which essentially governs the binding fit of mutative nitrogenate intermediates in the context of synergistic catalysis. The POVs-Cuδ+-TiO2 delivers a near-unity Faradaic efficiency (product basis 95.0%) and remarkable ammonia yield rate up to 1321.2 μmol h–1 mgcat–1 at −0.7 V vs RHE. This study underscores the surface topography engineering on reduced metal oxides and the promising synergistic effects over the NO3RR electrocatalysis, providing a better alternative for nitrate wastewater pollution treatment and ammonia production.