title: Heat of adsorption of naphthalene on Pt(111) measured by adsorption calorimetry.
abstract: The heat of adsorption of naphthalene on Pt(111) at 300 K was measured with single-crystal adsorption calorimetry. The heat of adsorption on the ideal, defect-free surface is estimated to be (300 - 34 - 199(2)) kJ/mol. From this, a C-Pt bond energy for aromatic hydrocarbons on Pt(111) of approximately 30 kJ/mol is estimated, consistent with earlier results for benzene on Pt(111). There is higher heat of adsorption at very low coverage, attributed to step sites where the adsorption heat is >/=330 kJ/mol. Saturation coverage, = 1 ML, corresponds to 1.55 x 10(14) molecules/cm(2). Sticking probability measurements of naphthalene on Pt(111) give a high initial value of 1.0 and a Kisliuk-type coverage dependence that implies precursor-mediated sticking. The ratio of the hopping rate to the desorption rate of this precursor is approximately 51. Naphthalene adsorbs transiently on top of chemisorbed naphthalene molecules with a heat of adsorption of 83-87 kJ/mol.
authors.affiliation: Department of Chemistry, Box 351700, University of Washington, Seattle, Washington 98195-1700, USA.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Gottfried
authors.forename: Ebbe K
authors.initials: EK
authors.lastname: Vestergaard
authors.forename: Parthasarathi
authors.initials: P
authors.lastname: Bera
authors.forename: Charles T
authors.initials: CT
authors.lastname: Campbell