• Cobalt;
  • CO2 activation;
  • Electrocatalysis;
  • Electrochemistry;
  • Reduction


A binuclear cobalt complex, [Co2BPP], derived from the (R,R)-Trost-bis-ProPhenol (BPP) ligand, has been investigated as a catalyst for CO2 uptake and its electrochemical reduction. The complex exhibits labile acetate ligands that can be readily exchanged with CO2, leading to pronounced changes in its vibrational spectra, with νC=O peaks observed at 1700 and 1596 cm–1. The electrochemical reduction of the CoIII centers at –0.5 V was significantly enhanced in the presence of CO2, evidencing a chemical reaction coupled to an electrode process. Instead of yielding CO or HCOOH as observed in most artificial systems, formaldehyde was identified as the major product below –1.0 V, showing that CO2 can undergo four-electron reduction by the [Co2BPP] electrocatalyst.