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

The high-rate ethanol electrosynthesis from CO 2 is challenging due to the low selectivity and poor activity, which requires the competition with other reduction products and H 2 . Here, the electrochemical reconstruction of Cs 3 Cu 2 Cl 5 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 CO 2 -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 CO 2 or CO reduction. This work suggests an attractive strategy with surface alkali-metal cations for ampere-level CO 2 -to-ethanol electrosynthesis.