| dc.description.abstract | Molecular catalysts for the electrochemical reduction of CO2 are being investigated for the potential utilization of CO2 as a viable C1 feedstock for the chemical industry and energy economy. Various CO2 reduction products can be generated such as CO, CH3OH, and CH4. Among the several multi-electron reduction products, this study focuses on the proton-coupled, two-electron reduction of CO2 to generate selectively CO (and H2O as the byproduct).
Several examples of selective CO2 reduction electrocatalysts, such as Ni(cyclam)^2+, cobalt macrocyclic compounds based on azacalix[4](2,6)pyridines, and FeTDHPP (TDHPP = tetrakis(2',6'-dihydroxylphenyl)porphyrin), feature protic N-H or O-H groups in the vicinity of the reactive metal ion. Hydrogen-bonding like interactions between N-H groups and reduced CO2 intermediates are proposed to stabilize transition states in Ni(cyclam)^2+ and cobalt macrocyclic compound, and the O-H groups in FeTDHPP are found to increase catalytic activity by acting as local proton sources.
Inspired by these reports, this study examines the effects of the interactions from the secondary coordination sphere of well-studied Lehn-type catalyst systems for CO2 reduction. Lehn-type pre-catalysts feature Re(CO)3X (X = Cl, Br, and py) moieties coordinated to bipyridine or phenanthroline chelators and have been previously shown to be highly selective for CO2 reduction. | en |
