Non-Aqueous Electrochemical CO₂ Reduction to Multivariate C₂-Products Over Single Atom Catalyst at Current Density up...

Electrochemical CO₂ reduction reaction (CO₂-RR) in non-aqueous electrolytes offers significant advantages over aqueous systems, as it boosts CO₂ solubility and limits the formation of HCO₃ ^- and CO₃ ^2- anions. Metal-organic frameworks (MOFs) in non-aqueous CO₂-RR makes an attractive system for CO₂ 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 CO₂-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 C₂ 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 C₂ 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 CO₂ reduction, benchmarking PCN-222(Cu) for MOF-based SAC electrocatalysis.