Abstract
Electrochemical CO(2) reduction reaction (CO(2)-RR) in non-aqueous electrolytes offers significant advantages over aqueous systems, as it boosts CO(2) solubility and limits the formation of HCO(3) (-) and CO(3) (2-) anions. Metal-organic frameworks (MOFs) in non-aqueous CO(2)-RR makes an attractive system for CO(2) capture and conversion. However, the predominantly organic composition of MOFs limits their electrical conductivity and stability in electrocatalysis, where they suffer from electrolytic decomposition. In this work, electrically conductive and stable Zirconium (Zr)-based porphyrin MOF, specifically PCN-222, metalated with a single-atom Cu has been explored, which serves as an efficient single-atom catalyst (SAC) for CO(2)-RR. PCN- 222(Cu) demonstrates a substantial enhancement in redox activity due to the synergistic effect of the Zr matrix and the single-atom Cu site, facilitating complete reduction of C(2) species under non-aqueous electrolytic conditions. The current densities achieved (≈100 mA cm(-) (2)) are 4-5 times higher than previously reported values for MOFs, with a faradaic efficiency of up to 40% for acetate production, along with other multivariate C(2) products, which have never been achieved previously in non-aqueous systems. Characterization using X-ray and various spectroscopic techniques, reveals critical insights into the role of the Zr matrix and Cu sites in CO(2) reduction, benchmarking PCN-222(Cu) for MOF-based SAC electrocatalysis.