Tailoring *CO adsorption in tandem catalysis for boosting CO₂ electroreduction

The electrochemical CO₂ reduction reaction (CO₂RR) to multi-carbon (C₂₊) products relies predominantly on Cu-based catalysts, but achieving high selectivity and efficiency remains challenging. The formation of C₂₊ products generally involves *CO generation and subsequent dimerization, making the modulation of *CO adsorption behavior critical. Herein, we developed N doped carbon nanosheets supported monatomic Ni and ultrafine oxide-derived Cu in amorphous state as a tandem catalyst. The Ni-N₄ sites enable a high *CO coverage, while the amorphization of the oxide-derived Cu nanoparticles induces a shift in the *CO adsorption configuration from atop to bridging, thereby facilitating the C–C coupling. These integrated effects endow the catalyst with exceptional performance, achieving a record Faradaic efficiency of ~ 70% for C₂₊ products and ~ 54% for C₂H₄. This work provides a strategy for designing tandem catalyst for CO₂RR multiscale component interaction.