Abstract
Using a variety of organic carbonyl molecules (R1C(O)R 2) and the rutile TiO2(1 1 0) surface as a model photocatalyst, we demonstrate both experimentally and theoretically that ejection of organic radicals from TiO2 surfaces is likely a prevalent reaction process occurring during heterogeneous photooxidation of organic molecules. Organic carbonyls react with coadsorbed oxygen species to form organic diolates which are more strongly bound to TiO2 than are the parent carbonyls. The parent carbonyls, when bound to TiO2(1 1 0) in an ν1 configuration, are photo-inactive toward valence band holes. However, the diolates are shown to photodecompose by ejection of one of the two R substituents from the surface into the gas phase, leaving behind the carboxylate of the other R group. Theoretical calculations using DFT show that in most cases the choice of which R group is ejected can be predicted based on the C-R bond energies and, to a lesser extent, the stability of the ejected R group.
| Original language | English |
|---|---|
| Pages (from-to) | 205-212 |
| Number of pages | 8 |
| Journal | Journal of Catalysis |
| Volume | 279 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Apr 1 2011 |
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Keywords
- DFT
- Photocatalysis
- Photodesorption
- Radicals
- Surface
- Theory
- TiO
ASJC Scopus subject areas
- Catalysis
- Physical and Theoretical Chemistry
Cite this
Generation of organic radicals during photocatalytic reactions on TiO 2 . / Henderson, M. A.; Deskins, N. A.; Zehr, R. T.; Dupuis, Michel.
In: Journal of Catalysis, Vol. 279, No. 1, 01.04.2011, p. 205-212.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Generation of organic radicals during photocatalytic reactions on TiO 2
AU - Henderson, M. A.
AU - Deskins, N. A.
AU - Zehr, R. T.
AU - Dupuis, Michel
PY - 2011/4/1
Y1 - 2011/4/1
N2 - Using a variety of organic carbonyl molecules (R1C(O)R 2) and the rutile TiO2(1 1 0) surface as a model photocatalyst, we demonstrate both experimentally and theoretically that ejection of organic radicals from TiO2 surfaces is likely a prevalent reaction process occurring during heterogeneous photooxidation of organic molecules. Organic carbonyls react with coadsorbed oxygen species to form organic diolates which are more strongly bound to TiO2 than are the parent carbonyls. The parent carbonyls, when bound to TiO2(1 1 0) in an ν1 configuration, are photo-inactive toward valence band holes. However, the diolates are shown to photodecompose by ejection of one of the two R substituents from the surface into the gas phase, leaving behind the carboxylate of the other R group. Theoretical calculations using DFT show that in most cases the choice of which R group is ejected can be predicted based on the C-R bond energies and, to a lesser extent, the stability of the ejected R group.
AB - Using a variety of organic carbonyl molecules (R1C(O)R 2) and the rutile TiO2(1 1 0) surface as a model photocatalyst, we demonstrate both experimentally and theoretically that ejection of organic radicals from TiO2 surfaces is likely a prevalent reaction process occurring during heterogeneous photooxidation of organic molecules. Organic carbonyls react with coadsorbed oxygen species to form organic diolates which are more strongly bound to TiO2 than are the parent carbonyls. The parent carbonyls, when bound to TiO2(1 1 0) in an ν1 configuration, are photo-inactive toward valence band holes. However, the diolates are shown to photodecompose by ejection of one of the two R substituents from the surface into the gas phase, leaving behind the carboxylate of the other R group. Theoretical calculations using DFT show that in most cases the choice of which R group is ejected can be predicted based on the C-R bond energies and, to a lesser extent, the stability of the ejected R group.
KW - DFT
KW - Photocatalysis
KW - Photodesorption
KW - Radicals
KW - Surface
KW - Theory
KW - TiO
UR - http://www.scopus.com/inward/record.url?scp=79952455722&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79952455722&partnerID=8YFLogxK
U2 - 10.1016/j.jcat.2011.01.021
DO - 10.1016/j.jcat.2011.01.021
M3 - Article
VL - 279
SP - 205
EP - 212
JO - Journal of Catalysis
JF - Journal of Catalysis
SN - 0021-9517
IS - 1
ER -