Nanocurvature‐Steered Interfacial Hydrogen Shuttle for Bosting Electrocatalytic Low‐Concentration NO Reduction to Ammonia

Abstract Electrochemical flue gas denitrification offers an appealing route to convert industrial nitrogen oxides to ammonia, through which nitrogen resource can be recovered, tackling both environmental and energy challenges. During NO electrochemical reduction, efficient water dissociation to supply active hydrogen (H ^* ) and steerable capacity to restrain undesired H ^* –H ^* dimerization is crucial. A hydrogen shuttle mediated NO reduction is demonstrated over the RuCu alloy loaded 3D carbon substrate (RuCu@HMNC) that enriched nanocurvature for NO concentration, which decoupled H ^* generation and recombination, realized superior ammonia Faradaic efficiency of 99.3% and yield of 626.47 µg h ⁻¹ cm ⁻² with dilute NO (10 vol.%) or 94.9% and 476 µg h ⁻¹ cm ⁻² for even 1 vol.% NO, far beyond its flat counterpart and most reported electrocatalysts. Superior to the conventional proton‐coupled electron transfer (PCET) mechanism, atomic hydrogen shuttle occurred thermodynamically for the crucial reaction step ( ^* NO‐ ^* NHO) over RuCu@HMNC. A hybrid electrocatalysis is further built, converting NO over both cathode and anode to produce ammonium and nitrate fertilizer. As a proof of concept, Zn‐NO battery with RuCu@HMNC cathode is assembled to simultaneous the dilute NO removal and NH ₃ synthesis. The power densities are recorded 3.47 (10 vol.% NO), with the corresponding NH ₃ yields of 852.22 µg h ⁻¹ cm ⁻² .