Covalent Attachment of a Rhenium Bipyridyl CO₂ Reduction Catalyst to Rutile TiO₂

Abstract

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

Light-Driven Heterogeneous Reduction of Carbon Dioxide: Photocatalysts and Photoelectrodes

“…Batista, Lian, and co-workers have determined the vibrational spectra of carboxylate-bound rhenium bipyridine catalysts on (001) TiO 2 single-crystal surfaces using calculations to study their conformations, but did no CO 2 reduction studies. 197 210 Yields as high as 400 ppm of CO g −1 h −1 were achieved in the first 30 min of the reaction using small amounts of RuO x as a co-catalyst and Na 2 SO 3 as a sacrificial hole scavenger. However, the yields quickly decayed within the first hour.…”

Dye aggregation identified by vibrational coupling using 2D IR spectroscopy

“…Re-based dyes have been extensively studied over the last 10 years as model systems for charge injection into TiO 2 and other semiconductors. 12,[32][33][34][35][36] From a comparison to density functional theory (DFT) calculations of the frequencies, we concluded that the dyes attached to the TiO 2 as either monomers or aggregates of two or three molecules, because the coupling between metal carbonyl groups is large enough to excitonically delocalize the vibrations across multiple carbonyl groups on adjacent molecules. 31 An illustration of FIG.…”

Molecular Catalyst Immobilized Photocathodes for Water/Proton and Carbon Dioxide Reduction

“…[3,[10][11][12][13][14][15][16][17] Ta king into account the effective charge-separation processes for water splitting/CO 2 reduction as well as issues associated with separation of the products, at andemP EC device with separated electrodes to perform differenthalf-reactions becomes more favorable. [3,[10][11][12][13][14][15][16][17] Ta king into account the effective charge-separation processes for water splitting/CO 2 reduction as well as issues associated with separation of the products, at andemP EC device with separated electrodes to perform differenthalf-reactions becomes more favorable.…”