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

Journal Article · Thu Jul 01 00:00:00 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), Vol. 11:4; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

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