Chinese Journal of Catalysis ›› 2016, Vol. 37 ›› Issue (10): 1684-1693.DOI: 10.1016/S1872-2067(16)62452-X

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Formation and removal of active oxygen species for the non-catalytic CO oxidation on Au/TiO2 catalysts

Daniel Widmann, R. Jürgen Behm   

  1. Institute of Surface Chemistry and Catalysis, Ulm University, Albert-Einstein-Allee 47, D-89081 Ulm, Germany
  • Received:2016-04-15 Revised:2016-05-06 Online:2016-10-21 Published:2016-10-22
  • Contact: R. Jürgen Behm

Abstract:

Applying quantitative temporal analysis of products reactor measurements, we studied the reactive removal of active oxygen present on Au/TiO2 catalysts after calcination at elevated temperatures (400℃) by CO pulses and its replenishment by O2 pulses at 80℃, focusing on the nature of the active oxygen species. In contrast to previous studies, which mainly focused on and clarified the nature of the active oxygen species for the catalytic CO oxidation, which is reversibly formed and replenished under typical reaction conditions, this study demonstrates that directly after calcination an additional oxygen species is present. This species is also active for the CO oxidation, but it is not or only very little formed under typical reaction conditions. Implications of these results on the mechanistic understanding of the CO oxidation on Au/TiO2, in particular on the role of different active oxygen species, will be discussed.

Key words: Titanium dioxide, Gold catalysis, Carbon monoxide oxidation, Reaction mechanism, Active oxygen, Temporal analysis of products