Hydrogenation of CO2 with the use of non-precious metal complexes
Barnes, Marie Annette
MetadataShow full item record
Hydrogenation of CO2 to formic acid is usually performed with precious metal catalysts. However, due to the cost and scarcity of precious metals, recent research has focused instead on first row transition metals. Of specific interest to our group are bis-phosphine and carbene complexes of iron, cobalt and nickel. Initial efforts found catalytically active species, which generated decent turn over numbers (TON). It was found that 10 different metals have at least some catalytic activity for this reaction, when combined with 1,2-bis(dimethylphosphino)ethane, including Fe, Co, Ni, In, Zn and Mo. The most active was an iron complex that had a TON of 726, High pressure NMR spectra obtained throughout the course of the reaction provide insight by which FeCl2(dmpe)2 hydrogenates CO2 to formic acid. As part of a search for CO2 hydrogenation catalysts base upon abundant metals efficient catalysts with carbene ligands were also found. The combination of either FeCl2, Ni(OAc)2, CoCl2 and Co(OAc)2 with various carbene or carbene precursors from catalysts in situ capable of hydrogenating CO2 to formic acid with TONs of up to 420.