Supported Cu/Ni Bimetallic Cluster Electrocatalysts Boost CO Reduction.

Supported metal clusters with the integrated advantages of single-atom catalysts and conventional nanoparticles held great promise in the electrocatalytic carbon dioxide reduction (ECOR) 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 ECOR. 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 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 HO dissociation, thereby accelerate the hydrogenation of CO to *COOH and the overall reaction process.