Dosed on rutile TiO2(110) at 100 K, the thermal chemistry of 2-propanol in three forms—C3H7OH, C3D7OD and C3H7OD—was characterized using temperature programmed desorption. Only 2-propanol, propene and water desorb with no evidence for acetone. The propene forms and desorbs by two paths, a heretofore unreported low temperature path extending from 300 to 450 K and, concerning with prior work, a high temperature path peaking between 565 and 575 K. Both paths exhibit isotope effects. The high temperature path is interpreted in terms of decomposition of 2-propoxy species located on bridging oxygen atom rows. The low temperature path is attributed to 2-propanol dehydration on under-coordinated Ti4+ ions of the Ti4+ rows. The low temperature path characteristics vary with the long range order and bridge-bonded oxygen atom vacancy concentration.
Revised: April 7, 2011 |
Published: July 26, 2007
Citation
Bondarchuk O., Y. Kim, J.M. White, J. Kim, B.D. Kay, and Z. Dohnalek. 2007.Surface Chemistry of 2-Propanol on TiO2(110): Low and High Temperature Dehydration, Isotope Effects, and Influence of Local Surface Structure.Journal of Physical Chemistry C 111, no. 29:1105-11067.PNNL-SA-54619.doi:10.1021/jp072298m