(560cc) Isolated Diatomic Fe-Ni Metal-Nitrogen Sites for Synergistic Electroreduction of CO2

Pyrolyzed carbon-based M-N_x materials with single-atom structures from MOFs have recently attracted increasing research attention. Compared to the traditional porous materials, M-N_x materials show some specific advantages, such as the structural diversity, easily functionalized, good designability and high specific surface area. However, the fabrication and identification of such active site remain difficult to achieve, and the limited density of isolated M-N_x sites greatly limit the enhance of activity. Here, we report isolated diatomic Fe-Ni sites anchored on nitrogenated carbon as an efficient electrocatalyst for CO₂ reduction. Ni-doped precursor is explored to controlling iron metal dispersity in ZIF-8 precursors. After pyrolysis, Fe-Ni-N_x sites are formed with porous structures. The best catalyst is loaded 10%wt. Fe with 3%wt. Ni, exhibiting high selectivity with CO Faradaic efficiency over a wide potential range from -0.5 to -0.9 V, and robust durability with 90% of its initial selectivity after 10 hours of electrolysis. The high exposed Fe-Ni-N_x sites demonstrate excellent mass activity toward CO₂ reduction, outperforming most reposted Fe-Ni-N_x materials.