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Description
CO₂ electrocatalytic reduction reaction allows to convert environmentally harmful CO₂ into useful chemicals. To this aim, Cu stands out as the only catalyst capable of producing valuable hydrocarbons and alcohols, such as ethylene and ethanol.1-2
The catalyst surface structure plays a key role in determining the selectivity towards certain carbon products; in particular, vicinal surfaces were studied to find connections between active sites and selectivity. Earlier works on electropolished surface suggest that Cu(310), i.e. Cu(S)–[3(100) × (110)], produces the highest amount of ethanol.3-4
Following recent works on UHV-prepared Cu(111) and (100) surface, we proved in this work that metallic Cu(310) single crystal does not reduce CO₂, but rather H₂O to H₂; indeed, we identified that only for oxidized surface CO₂ is converted to carbon products. We measured the Faradaic Efficiencies (FEs) of the UHV-prepared Cu(310) single crystal. It initially produces C products but switches gradually to only hydrogen in ≈1h. After the transition, different stimuli were applied and only an oxidative electrochemical stimulus lead to the formation of carbon products, with a total FE for gaseous products of ≈30%. X-Ray Photoelectron Spectroscopy (XPS), Low Energy Electron Diffraction (LEED), and Scanning Electron Microscopy (SEM) allowed us to investigate the Cu oxidation states, surface long-range order, and surface morphology, respectively.
- J. W. Shi et al., ACS Nano, 18, 21714−21746, 2024
- Chorkendorff et al., Chem. Rev., 119, 7610−7672, 2019
- Y. Hori et al., Journal of Molecular Catalysis A: Chemical 199, 39–47, 2003
- H.T. Jung et al., ACS Catal., 11, 9, 5658–5665, 2021
