Promoting dilute CO2 electrolysis with electron-withdrawing ligand modification

The efficient production of valuable multicarbon (C 2+ ) chemicals via direct electrolysis of dilute CO 2 derived from industrial flue gases is a promising route to close the carbon cycle, but is not yet practical owing to insufficient electrocatalytic performance limited by sluggish reaction kinetics at low CO 2 concentrations. Herein, we develop BDC- X (where BDC represents 1,4-benzenedicarboxylic acid and X represents H, F, and NH 2 ) ligand-modified Cu nanoparticle catalysts via in-situ electrochemical reconstruction of metal organic frameworks precursors, for dilute CO 2 electrolysis to C 2+ products. The - X functional groups anchored on the BDC can be deemed as site-specific regulators for modulating the electronic structure of Cu nanoparticles. The BDC-F ligand with strong electron-withdrawing ability exhibits the most remarkable promoting effect, with an impressive C 2+ Faradaic efficiency of 67.9% and a maximum C 2+ partial current density of 130 mA cm −2 under a 15% CO 2 feed at 0.4 MPa. Combined experimental and theoretical investigations indicate that the reduced electron density of Cu active sites induced by the electron-withdrawing -F group improves *CO adsorption and lowers energy barrier for C−C coupling, thus resulting in improved C 2+ selectivity.