Synergistic surface modification of Cu with schiff-base networks for high selectivity and durability in CO₂-to-C₂H₄ electroreduction.

Abstract

The electrocatalytic CO₂ reduction reaction (e-CO₂RR) on Cu-based catalysts has been extensively studied; however, achieving high selectivity for C₂₊ products and long-term durability remains challenging. Here, we introduce a straightforward approach that enhances both C₂H₄ selectivity and catalyst durability by incorporating a nitrogen-rich Schiff-base Network (SNW), leveraging a synergistic interaction between Cu and SNW. Notably, Cu cubes with SNW, predominantly exposing the Cu(200) facet, achieve a Faradaic Efficiency (FE) of 71.2% for C₂H₄ at a current density of 265 mA cm^-2, which not only exceeds tetrahedral and spherical Cu with or without SNW, but also ranks competitively among state‑of‑the‑art Cu-based catalysts reported to date. Theoretical calculations suggest that the presence of SNW on Cu facilitates the *CO-*CHO coupling and/or the C₂H₄ desorption, thereby enhancing C₂H₄ formation. Furthermore, the Cu(200)-SNW surface exhibits optimized Gibbs free energies for the reaction steps compared to bare Cu and other SNW-modified Cu surfaces, which rationalizes the experimental observations. In situ electron microscopy further suggests that SNW confers durability by stabilizing Cu facets and preventing corrosion and dissolution under reaction conditions.