Atomically Engineered RuO_x-Cu Interfaces Enabling Tandem Catalysis for Ampere-Level Nitrite-Ethanol Co-Electrolysis

Designing tandem catalysts with well-defined interfacial architectures is of great significance for promoting multi-step electrochemical transformations, yet achieving synergistic regulation of dual active sites at the atomic level remains a formidable challenge. Herein, we develop an atomic-level engineering strategy to construct RuO_x cluster-modified Cu-based nanowire array electrodes with abundant interfacial structures, which act as efficient tandem catalysts for sustained nitrite-ethanol paired electrolysis at ampere-level current densities. In situ spectroscopic analysis combined with theoretical calculations reveals that the atomically RuO_x cluster serves as highly active water-activation sites, generating abundant active hydrogen/oxygen species that subsequently react with adsorbed nitrogen and carbon-containing intermediates, thereby enabling exceptionally favorable co-electrolysis kinetics. Impressively, a membrane electrode assembly flow electrolyzer constructed with RuO_x@R-Cu/CF as both electrodes achieves >90% Faradaic efficiencies for NH₃ and acetate over a wide current density window of 0.2-1.0 A cm^-2, along with high yields of 5.86 mmol h^-1 cm^-2 (NH₃) and 8.65 mmol h^-1 cm^-2 (acetate) at 1.0 A cm^-2, and outstanding operational stability, significantly surpassing previously reported co-electrolysis systems.