Dynamically Reconstructed Cu Nanowire Arrays Realizing Efficient Industrial-Current-Density CO2-to-C2+ Electroreduction

Selective C2+ production at industrial current densities is highly desirable but still colossally challenging, even for typical Cu-based catalysts. To address these issues, self-supporting Cu nanowire arrays assembled on a gas diffusion layer are first fabricated by in situ electroreduction of Cu(OH)2 nanowire arrays, while in situ X-ray diffraction patterns and in situ Raman measurements monitor their dynamic phase transformation process. The finite-element method calculations elucidate that the nanowire array structure enriches the local concentration of CO2/CO, further verified by operando Raman spectra. In situ attenuated total reflection-surface-enhanced infrared absorption spectroscopy reveals the Cu nanowire arrays promote *CO dimerization into *OCCO intermediates. Based on the above merits, the Cu nanowire arrays achieve a high Faradaic efficiency of 75.4% for C2+ products with a current density of 500 mA cm-2. Overall, this study provides new insights into designing array catalysts for creating confined spaces to enrich reactants and intermediates.