COLL 243 |
| Ilkeun Lee and Francisco Zaera. Department of Chemistry, University of California, Riverside, CA 92521 |
| The thermal reactions of various C4 hydrocarbons on Pt(111) were investigated by temperature-programmed desorption and reflection-absorption infrared spectroscopy. This is an extension of previous work from our group to try to understand the mechanism for double bond migrations. It was found that on clean Pt(111), thermal activation leads to the desorption of hydrogen, butene (260 K), and/or butane (240 K). Butene desorption was enhanced or occurred at lower temperature by predosed hydrogen. The hydrogenation of 1-butyl to butane is also enhanced by predosed hydrogen, but 2-butyl mostly β-H dehydrogenates to butene. 1,2-di-σ bonded butene prefers to undergo double bond migration rather than 1-butyl formation, perhaps because of steric hindrance. Double bond migration from 2-butene to 1-butene was not seen. The formation of η3 butyl was supported by the high desorption temperature of butene above 280 K. |
|
Posters: Fundamental Research in Surface and Colloid Chemistry
6:00 PM-8:00 PM, Monday, March 29, 2004 Disneyland -- North Exhibit Hall, Poster
Division of Colloid and Surface Chemistry |