Abstract
Temperature-programmed desorption (TPD), Auger electron spectroscopy (AES), and low-energy electron diffraction (LEED) were used to study the chemistry of 1,3-butadiene (H2C=CHCH=CH2, C4H6) on Pt(111) and p(2 × 2)-Sn/Pt(111) and (√3 × √3)R30°-Sn/Pt(111) surface alloys. All chemisorbed 1,3-butadiene completely dehydrogenated to H2 and surface carbon on Pt(111). Alloying Sn on Pt(111) can completely inhibit this decomposition and 1,3-butadiene reversibly adsorbs and desorbs from the two Sn/Pt(111) alloys under UHV conditions. The desorption activation energy of 1,3-butadiene on the (2 × 2) and (√3 × √3)R30°-Sn/Pt(111) surface alloys is 88 and 75kJ/mol, respectively. These values are good estimates of the adsorption energies, and also place lower limits on the activation energy barrier for dissociating vinylic C-H bonds on the (2 × 2) and √3 surface alloys. Even though 1,3-butadiene is much more strongly chemisorbed than 1-butene (H2C=CHCH2CH3, C4H 8) on the (2 × 2)-Sn/Pt(111) alloy, 1,3-butadiene is less reactive than 1-butene because there are no allylic β-CH bonds in 1,3-butadiene as there are in 1-butene.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 261-268 |
| Number of pages | 8 |
| Journal | Surface Science |
| Volume | 572 |
| Issue number | 2-3 |
| DOIs | |
| State | Published - Nov 20 2004 |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry
Keywords
- Alkenes
- Alloys
- Auger electron spectroscopy
- Chemisorption
- Low energy electron diffraction (LEED)
- Platinum
- Thermal desorption
- Tin