Over 2 A cm^-2 CO₂ -to-Ethanol Conversion by Alkali-Metal Cation Induced Copper With Dominant (200) Facets

The high-rate ethanol electrosynthesis from CO₂ is challenging due to the low selectivity and poor activity, which requires the competition with other reduction products and H₂ . Here, the electrochemical reconstruction of Cs₃ Cu₂ Cl₅ perovskite to form surface Cl-bonded, low-coordinated Cs modified Cu(200) nanocubes (CuClCs), is demonstrated. Density functional theory calculations reveal that the CuClCs structure possesses low Bader charges and a large coordination capacity; and thus, can promote the CO₂ -to-ethanol pathway via stabilizing C-O bond in oxygenate intermediates. The CuClCs catalyst exhibits outstanding partial current densities for producing ethanol (up to 2124 ± 54 mA cm^-2 ) as one of the highest reported values in the electrochemical CO₂ or CO reduction. This work suggests an attractive strategy with surface alkali-metal cations for ampere-level CO₂ -to-ethanol electrosynthesis.