Preparation of nickel and palladium electrocatalysts for the reduction of CO₂

One approach to the conversion of carbon dioxide into a more valuable chemical commodity is through its electrocatalytic reduction. A series of palladium compounds supported by triphosophine ligands has previously been reported to be effective electrocatalysts for the reduction of CO2 to CO. In addition, a bimetallic catalyst that incorporated two [Pd(triphosphine)(solvent)]2+ units was found to very selectively reduce CO2 to CO at rates comparable to the [NiFe] CO dehydrogenase enzyme, but was plagued by very short catalyst lifetimes. The work to be presented includes several ligand modifications as well as the preparation of analogous nickel complexes in order to further probe structure-activity relationships among this class of catalysts. Novel bimetallic catalysts intended to mimic the cooperative chemistry of the [NiFe] CO dehydrognenase have been prepared and characterized, and their ability to electrocatalytically reduce CO2 will be discussed.