Supported Cu/Ni Bimetallic Cluster Electrocatalysts Boost CO₂ Reduction

Supported metal clusters with the integrated advantages of single-atom catalysts and conventional nanoparticles held great promise in the electrocatalytic carbon dioxide reduction (ECO₂R) operated at low overpotential and high current density. However, its precise synthesis and the understanding of synergistically catalytic effects remain challenging. Herein, we report a facile method to synthesize the bimetallic Cu and Ni clusters anchored on porous carbon (Cu/Ni-NC) and achieve an enhanced ECO₂R. The aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and synchrotron X-ray absorption spectroscopy were employed to verify the metal dispersion and the coordination of Cu/Ni clusters on NC. As a result of this route, the target Cu/Ni-NC exhibits excellent electrocatalytic performance including a stable 30 h electrolysis at 200 mA cm^-2 with carbon monoxide Faradaic efficiency of ∼95.1% using a membrane electrode assembly electrolysis cell. Combined with the in situ analysis of the surface-enhanced Fourier transform infrared spectroelectrochemistry, we propose that the synergistic effects between Ni and Cu can effectively promote the H₂O dissociation, thereby accelerate the hydrogenation of CO₂ to *COOH and the overall reaction process.