Adsorption and desorption of CO and H2 on Rh(111): Laser-induced desorption

E. G. Seebauer, A. C.F. Kong, L. D. Schmidt

Research output: Contribution to journalArticle

Abstract

Isosteric heats of adsorption ΔHad of CO and sticking coefficients S for CO and H2 on Rh(111) are determined by laser-induced thermal desorption (LITD) in which a pulsed laser beam is focused onto the surface, and rapid local heating yields a desorption signal that is proportional to the adsorbate coverage θ. ΔHad for CO falls from 32.0±2 kcal/mol at low coverage to 14 kcal/mol at saturation, and the desorption pre-exponential factor vd decreases from 1014±0.5 to 1010 s-1. ΔHad, vd, and S of CO all decline sharply above θ = 0.2, corresponding to the occupation of a second binding state. Sticking coefficients for CO and hydrogen indicate precursor intermediates in adsorption.

Original languageEnglish (US)
Pages (from-to)163-172
Number of pages10
JournalApplied Surface Science
Volume31
Issue number1
DOIs
StatePublished - Jan 1988
Externally publishedYes

    Fingerprint

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Physics and Astronomy(all)
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

Cite this