Photocatalytic oxidation of cyclohexane over TiO2: Evidence for a Mars-van krevelen mechanism

A.R. Almeida, Ana Rita Almeida, Jacob A. Moulijn, Guido Mul

Research output: Contribution to journalArticleAcademicpeer-review

38 Citations (Scopus)

Abstract

Cyclohexane photocatalytic oxidation with 18O2 over anatase TiO2 was analyzed by in situ attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, to gain insight in the mechanistic steps of formation of cyclohexanone and deactivating carboxylate species, respectively. Cyclohexane photo-oxidation on TiO2 with increasing concentration of labeled Ti−18OH sites yielded cyclohexanone and surface deactivating species with an isotopic distribution reflecting the concentration of Ti−18OH sites on the surface. This finding suggests that oxygen incorporated in cyclohexanone, as well as in deactivating carbonates and carboxylates, originates from the catalyst surface, rather than from dissolved O2. Cyclohexyl hydroperoxide, observed spectroscopically, is a spectator species, rather than a commonly assumed reaction intermediate. The proposed Mars−van Krevelen cycle is completed by regeneration of surface sites by reaction with 18O2
Original languageEnglish
Pages (from-to)1330-1338
Number of pages9
JournalJournal of physical chemistry C
Volume115
Issue number4
DOIs
Publication statusPublished - 2011

Keywords

  • METIS-280545
  • IR-95292

Fingerprint Dive into the research topics of 'Photocatalytic oxidation of cyclohexane over TiO2: Evidence for a Mars-van krevelen mechanism'. Together they form a unique fingerprint.

Cite this