Microsecond kinetics of photocatalytic oxidation on Pt/TiO2 traced by vibrational spectroscopy

✍ Scribed by Akira Yamakata; Taka-aki Ishibashi; Hiroshi Onishi

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 185 KB
• Volume: 376
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/s0009-2614(03)01034-0

✦ Synopsis

2-Propanol oxidation to acetone was examined by time-resolved infrared spectroscopy on a Pt/TiO 2 photocatalyst in an aqueous solution. Holes generated by the band-gap excitation were found to attach to the adsorbed reactant within the first 0.5 ls. Subsequent rearrangement of atoms in the hole-attached reactant was observed on a series of timeresolved vibrational spectra. The C@O stretching band of a reaction intermediate to be converted to acetone appeared at time delays of 0-20 ls. The observed wavenumber of the intermediate, 1640 cm À1 , was compared with theoretically predicted C@O stretching frequencies of possible species. An acceptable agreement was obtained with the anion radical of acetone adsorbed on the catalyst.