Schießer, Alexander ; Hörtz, Peter ; Schäfer, Rolf (2023)
Thermodynamics and kinetics of CO and benzene adsorption on Pt(111) studied with pulsed molecular beams and microcalorimetry.
In: Surface Science, 2010, 604 (23-24)
doi: 10.26083/tuprints-00024246
Artikel, Zweitveröffentlichung, Postprint
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Kurzbeschreibung (Abstract)
The adsorption and desorption of the system CO/Pt(111) and C6H6/Pt(111) at 300 K has been investigated with a pulsed molecular beam method in combination with a microcalorimeter. For benzene the sticking probability has been measured in dependence of the coverage θ. For coverages θ > 0.8 transient adsorption is observed. From an analysis of the time-dependence of the molecular beam pulses the rate constant for desorption is determined to be 5.6 s− 1. With a precursor-mediated kinetic adsorption model this allows to obtain also the hopping rate constant of 95.5 s− 1. The measured adsorption enthalpies could be best described by (199 − 77θ − 51θ2) kJ/mol, in good agreement with the literature values. For CO on Pt(111) also transient adsorption has been observed for θ > 0.95 at 300 K. The kinetic analysis yields rate constants for desorption and hopping of 20 s−1 and 51 s−1, respectively. The heats of adsorption show a linear dependence on coverage (131 − 38θ) kJ/mol between 0 ≤ θ ≤ 0.3, which is consistent with the desorption data from the literature. For higher coverage (up to θ = 0.9ML) a slope of −63 kJ/mol describes the decrease of the differential heat of adsorption best. This result is only compatible with desorption experiments, if the pre-exponential factor decreases strongly at higher coverage. We found good agreement with recent quantum chemical calculations made for (θ = 0.5ML).
| Typ des Eintrags: | Artikel |
|---|---|
| Erschienen: | 2023 |
| Autor(en): | Schießer, Alexander ; Hörtz, Peter ; Schäfer, Rolf |
| Art des Eintrags: | Zweitveröffentlichung |
| Titel: | Thermodynamics and kinetics of CO and benzene adsorption on Pt(111) studied with pulsed molecular beams and microcalorimetry |
| Sprache: | Englisch |
| Publikationsjahr: | 2023 |
| Ort: | Darmstadt |
| Publikationsdatum der Erstveröffentlichung: | 2010 |
| Verlag: | Elsevier |
| Titel der Zeitschrift, Zeitung oder Schriftenreihe: | Surface Science |
| Jahrgang/Volume einer Zeitschrift: | 604 |
| (Heft-)Nummer: | 23-24 |
| DOI: | 10.26083/tuprints-00024246 |
| URL / URN: | https://tuprints.ulb.tu-darmstadt.de/24246 |
| Zugehörige Links: | |
| Herkunft: | Zweitveröffentlichungsservice |
| Kurzbeschreibung (Abstract): | The adsorption and desorption of the system CO/Pt(111) and C6H6/Pt(111) at 300 K has been investigated with a pulsed molecular beam method in combination with a microcalorimeter. For benzene the sticking probability has been measured in dependence of the coverage θ. For coverages θ > 0.8 transient adsorption is observed. From an analysis of the time-dependence of the molecular beam pulses the rate constant for desorption is determined to be 5.6 s− 1. With a precursor-mediated kinetic adsorption model this allows to obtain also the hopping rate constant of 95.5 s− 1. The measured adsorption enthalpies could be best described by (199 − 77θ − 51θ2) kJ/mol, in good agreement with the literature values. For CO on Pt(111) also transient adsorption has been observed for θ > 0.95 at 300 K. The kinetic analysis yields rate constants for desorption and hopping of 20 s−1 and 51 s−1, respectively. The heats of adsorption show a linear dependence on coverage (131 − 38θ) kJ/mol between 0 ≤ θ ≤ 0.3, which is consistent with the desorption data from the literature. For higher coverage (up to θ = 0.9ML) a slope of −63 kJ/mol describes the decrease of the differential heat of adsorption best. This result is only compatible with desorption experiments, if the pre-exponential factor decreases strongly at higher coverage. We found good agreement with recent quantum chemical calculations made for (θ = 0.5ML). |
| Freie Schlagworte: | Microcalorimetry, Sticking probability, Adsorption energies, Carbon monoxide, Benzene, Pt(111) |
| Status: | Postprint |
| URN: | urn:nbn:de:tuda-tuprints-242468 |
| Sachgruppe der Dewey Dezimalklassifikatin (DDC): | 500 Naturwissenschaften und Mathematik > 540 Chemie |
| Fachbereich(e)/-gebiet(e): | 07 Fachbereich Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Anorganische Chemie 07 Fachbereich Chemie > Eduard Zintl-Institut 07 Fachbereich Chemie > Eduard Zintl-Institut > Fachgebiet Physikalische Chemie |
| Hinterlegungsdatum: | 11 Jul 2023 07:15 |
| Letzte Änderung: | 02 Aug 2024 12:53 |
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- Thermodynamics and kinetics of CO and benzene adsorption on Pt(111) studied with pulsed molecular beams and microcalorimetry. (deposited 11 Jul 2023 07:15) [Gegenwärtig angezeigt]
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