Abstract
Hydrogenation of CO2 to formate serves as a means of H2 storage. By utilizing robust, electron-rich and bulky tetrazolyl ligands, active catalysts for CO2 hydrogenation can be prepared. We have prepared CO2 hydrogenation iridium(III) and palladium(II) catalyst precursors utilizing N^N bidentate tetrazolylpyridyl that operate in water as a solvent. Turnover numbers (TONs) of around 500 could be obtained using these N^N bidentate precatalysts at low catalyst loading. In situ 1H NMR spectroscopic data obtained when the hydrogenation catalyst was N^N bidentate tetrazolylpyridyl iridium(III), detected a hydrido bridged binuclear iridium intermediate compound that was formed prior to the formation of the catalytically active iridium hydride species...
D.Phil. (Chemistry)