Temperature-programmed desorption investigation of the adsorption and reaction of butene isomers on Pt(111) and ordered Pt-Sn surface alloys

Journal Article · Thu Apr 10 04:00:00 EDT 1997 · Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical

DOI:https://doi.org/10.1021/jp9638245· OSTI ID:512897

Tsai, Y L; Koel, B E ^[1]

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1. Univ. of Southern California, Los Angeles, CA (United States)

The influence of alloyed Sn on the chemistry of C{sub 4} butene isomers, including 1-butene, cis-2-butene, and isobutene, chemisorbed on Pt(111) was investigated by temperature-programmed desorption (TPD), Auger electron spectroscopy (AES), and low-energy electron diffraction (LEED). Pt-Sn alloy chemistry was probed by investigation of two ordered surface alloys formed when Sn atoms were incorporated within the topmost layer on a Pt(111) substrate. All three butenes undergo decomposition on Pt(111) during TPD which accounts for 50-60% of the chemisorbed monolayer. Alloying Sn into the surface causes a large reduction in the reactivity of the surface, and the fraction of the chemisorbed layer which decomposes is decreased to 3-7% on the (2 x 2) alloy, and no decomposition occurs on the ({radical}3 x {radical}3)R30{degree} alloy. The strong reduction of decomposition on these two surface alloys may be due to the elimination of adjacent pure Pt 3-fold hollow sites. No large changes occur in the coverage of chemisorbed monolayer of butenes in the presence of up to 33% of a monolayer of alloyed Sn, showing that the adsorption ensemble requirement for chemisorption of these alkenes on Pt(111) and the two Sn/Pt(111) alloys is at most a few Pt atoms. 39 refs., 15 figs., 1 tab.

• OSTI ID: 512897
• Journal Information: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Journal Name: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical Journal Issue: 15 Vol. 101; ISSN 1089-5647; ISSN JPCBFK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
ACTIVATION ENERGY
ADSORPTION
AUGER ELECTRON SPECTROSCOPY
BUTENES
CHEMICAL REACTIONS
DESORPTION
ELECTRON DIFFRACTION
ISOMERS
NUMERICAL DATA
ORDER PARAMETERS
PLATINUM ALLOYS
TEMPERATURE DEPENDENCE