Predosed oxygen temperature programmed desorption as a kinetic probe of dehydrogenation on Pt(111)

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578394· OSTI ID:5526677

Zhou, X; White, J M ^[1]

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1. Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712 (United States)

Based on the propensity of surface atomic oxygen O(a) to react fiercely with H(a) on Pt(111) to form water that desorbs at low temperature, we have developed a thermal reaction and desorption technique---predosed oxygen temperature programmed desorption (POTPD)---which is useful for probing the kinetics of dehydrogenation on Pt(111). The method relies on very low coverages of O(a) which react with available adsorbed atomic H to form water, which desorbs promptly. Thus, the H[sub 2]O temperature programmed desorption reflects the dehydrogenation process. We have successfully utilized POTPD to determine the dehydrogenation temperatures of methylene (CD[sub 2]), methyl (CD[sub 3]), vinyl (CHCH[sub 2]), ethylene (C[sub 2]D[sub 4]), ethyl (C[sub 2]D[sub 5]), thioethoxy (SC[sub 2]H[sub 5]), and diethyl sulfide [S(C[sub 2]H[sub 5])[sub 2]] on Pt(111). From the data, a mechanism and kinetic parameters for vinyl to ethylidyne conversion are presented.

• OSTI ID: 5526677
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 11:4; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKENES
ALKYL RADICALS
CHEMICAL BONDS
CHEMICAL REACTIONS
DEHYDROGENATION
DESORPTION
DEUTERIUM COMPOUNDS
ELEMENTS
ETHYL RADICALS
ETHYLENE
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
METALS
METHYL RADICALS
METHYLENE RADICALS
NONMETALS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PLATINUM
PLATINUM METALS
RADICALS
SORPTION
SORPTIVE PROPERTIES
SURFACE PROPERTIES
TRANSITION ELEMENTS
ULTRAHIGH VACUUM
VINYL RADICALS
WATER