Abstract
The reactions of C1-C4 aliphatic alcohols over (WO 3) 3 clusters were studied experimentally and theoretically using temperature-programmed desorption, infrared reflection-absorption spectroscopy, and density functional theory. The results reveal that all C1-C4 aliphatic alcohols readily react with (WO 3) 3 clusters by heterolytic cleavage of the RO-H bond to give alkoxy (RO-) bound to W(VI) centers and a proton (H +) attached to the terminal oxygen atom of a tungstyl group (WdO). Two protons adsorbed onto the cluster readily react with the doubly bonded oxygen to from a water molecule that desorbs at 200-300 K and the alkoxy that undergoes decomposition at higher temperatures into the corresponding alkene, aldehyde, and/or ether. Our theory predicts that all three channels proceed over the W(VI) Lewis acid sites with energy barriers of 30-40 kcal/mol, where dehydration is favored over the others. We also present further analysis of the yield and reaction temperature as a function of the alkyl substituents and discuss the origin of the reaction selectivity among the three reaction channels.
| Original language | English |
|---|---|
| Pages (from-to) | 9721-9730 |
| Number of pages | 10 |
| Journal | Journal of Physical Chemistry C |
| Volume | 113 |
| Issue number | 22 |
| DOIs | |
| Publication status | Published - Jun 4 2009 |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Energy(all)
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Competitive oxidation and reduction of aliphatic alcohols over (wo3)3 clusters. / Kim, Yu Kwon; Dohnálek, Z.; Kay, Bruce D.; Rousseau, Roger.
In: Journal of Physical Chemistry C, Vol. 113, No. 22, 04.06.2009, p. 9721-9730.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Competitive oxidation and reduction of aliphatic alcohols over (wo3)3 clusters
AU - Kim, Yu Kwon
AU - Dohnálek, Z.
AU - Kay, Bruce D.
AU - Rousseau, Roger
PY - 2009/6/4
Y1 - 2009/6/4
N2 - The reactions of C1-C4 aliphatic alcohols over (WO 3) 3 clusters were studied experimentally and theoretically using temperature-programmed desorption, infrared reflection-absorption spectroscopy, and density functional theory. The results reveal that all C1-C4 aliphatic alcohols readily react with (WO 3) 3 clusters by heterolytic cleavage of the RO-H bond to give alkoxy (RO-) bound to W(VI) centers and a proton (H +) attached to the terminal oxygen atom of a tungstyl group (WdO). Two protons adsorbed onto the cluster readily react with the doubly bonded oxygen to from a water molecule that desorbs at 200-300 K and the alkoxy that undergoes decomposition at higher temperatures into the corresponding alkene, aldehyde, and/or ether. Our theory predicts that all three channels proceed over the W(VI) Lewis acid sites with energy barriers of 30-40 kcal/mol, where dehydration is favored over the others. We also present further analysis of the yield and reaction temperature as a function of the alkyl substituents and discuss the origin of the reaction selectivity among the three reaction channels.
AB - The reactions of C1-C4 aliphatic alcohols over (WO 3) 3 clusters were studied experimentally and theoretically using temperature-programmed desorption, infrared reflection-absorption spectroscopy, and density functional theory. The results reveal that all C1-C4 aliphatic alcohols readily react with (WO 3) 3 clusters by heterolytic cleavage of the RO-H bond to give alkoxy (RO-) bound to W(VI) centers and a proton (H +) attached to the terminal oxygen atom of a tungstyl group (WdO). Two protons adsorbed onto the cluster readily react with the doubly bonded oxygen to from a water molecule that desorbs at 200-300 K and the alkoxy that undergoes decomposition at higher temperatures into the corresponding alkene, aldehyde, and/or ether. Our theory predicts that all three channels proceed over the W(VI) Lewis acid sites with energy barriers of 30-40 kcal/mol, where dehydration is favored over the others. We also present further analysis of the yield and reaction temperature as a function of the alkyl substituents and discuss the origin of the reaction selectivity among the three reaction channels.
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UR - http://www.scopus.com/inward/citedby.url?scp=67149123492&partnerID=8YFLogxK
U2 - 10.1021/jp8109463
DO - 10.1021/jp8109463
M3 - Article
VL - 113
SP - 9721
EP - 9730
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 22
ER -