Ultrafast molecular transport on carbon surfaces: The diffusion of ammonia on graphite

Anton Tamtögl, Marco Sacchi, Irene Calvo-Almazán, M. Zbiri, Marek M. Koza, W.E. Ernst, Peter Fouquet

Publikation: Beitrag in einer FachzeitschriftArtikelForschungBegutachtung

Abstract

We present a combined experimental and theoretical study of the self-diffusion of ammonia on exfoliated graphite. Using neutron time-of-flight spectroscopy we are able to resolve the ultrafast diffusion process of adsorbed ammonia, NH3, on graphite. Together with van der Waals corrected density functional theory calculations we show that the diffusion of NH3 follows a hopping motion on a weakly corrugated potential energy surface with an activation energy of about 4 meV which is particularly low for this type of diffusive motion. The hopping motion includes further a significant number of long jumps and the diffusion constant of ammonia adsorbed on graphite is determined with D=3.9⋅10−8m2/s at 94 K.

Originalspracheenglisch
Seiten (von - bis)23-30
Seitenumfang8
FachzeitschriftCarbon
Jahrgang126
DOIs
PublikationsstatusVeröffentlicht - 1 Jan 2018

Schlagwörter

    Fields of Expertise

    • Advanced Materials Science

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  • Projekte

    • 1 Abschlussdatum

    FWF - Oberflächen - Exotische Oberflächen

    Tamtögl, A.

    15/11/1314/01/17

    Projekt: Foschungsprojekt

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