Covalent attachment of a rhenium bipyridyl CO2 reduction catalyst to Rutile TiO2.

We have characterized the covalent binding of the CO2 reduction electrocatalyst ReC0A (Re(CO)(3)-Cl(dcbpy) (dcbpy =4,4'-dicarboxy-2,2'-bipyridine)) to the TiO2 rutile (001) surface. The analysis based on sum frequency generation (SFG) spectroscopy and density functional theory (DFT) calculations indicates that ReC0A binds to TiO2 through the carboxylate groups in bidentate or tridentate linkage motifs. The adsorbed complex has the dcbpy moiety nearly perpendicular to the TiO2 surface and the Re exposed to the solution in a configuration suitable for catalysis.