Atomic Editing Copper Twin Boundary for Precision CO₂ Reduction

Electrocatalysis involves multiphase interface, stepped charge transfer, intermediate adsorption, chemical bonding transformation, etc., all of which are linked to the special catalytic active centers on the electrodes. Especially, when different types of active centers meet on the surfaces, it is difficult to catalog and investigate quantitatively their cooperative catalytic behavior. Here, we report a strategy to precisely edit Sn atoms into the copper twin boundaries (TBs) through pulsed electrodeposition and boundary segregation. With the Sn atoms edited into the one-dimensional TB lattice, the formate Faradaic efficiency could be significantly improved up to 95% with a partial current density boosted by 431%. The edited Sn atom at TBs showed a turnover frequency of ∼4.6 × 104 s–1, ∼2 orders higher than the Sn dopants on the facet and pure Cu TB active centers. A theoretical thermodynamic analysis of the reaction energetics suggested that Sn at TBs could facilitate the formate generation while suppressing the hydrogen evolution and the CO production.