Width of particle beams desorbed in electron stimulated desorption: O+ and metastable CO from CO/Pt(111)

Szabó, András; Yates, John T.
January 1993
Journal of Chemical Physics;1/1/1993, Vol. 98 Issue 1, p689
Academic Journal
The role of adsorbate vibrations parallel to the surface on the width of particle beams escaping from the surface in electron stimulated desorption (ESD) has been studied. Chemisorbed CO on Pt(111) was employed as a model system. The angular distribution of O+ and of the metastable a 3π–CO (CO*) species desorbed in ESD was measured. A cluster calculation was used to model the CO vibration on Pt(111), from which it was possible to calculate the CO* and O+ ESDIAD (electron stimulated desorption-ion angular distribution) beam widths. For CO* we were able to calculate the width of the ESDIAD beams for θCO=0.15 ML with an accuracy better than the error bar of the measurement in the temperature range of 100–300 K. This calculation shows that the CO* angular distribution is related to both the bond direction and the parallel momentum of the surface oscillator at the time of excitation. For θCO=0.5 ML, the width of the measured and calculated values are in good agreement in the temperature range of 100–230 K; above 230 K the experimental results show a positive deviation from the calculated values, indicating that an extra broadening mechanism occurs above ∼230 K, probably because of the onset of an order–disorder transition. For the O+ ESDIAD beam widths the experimental results show a somewhat sharper distribution than the calculated values, most likely because of the angularly anisotropic neutralization rate that was not quantitatively considered in the calculation.


Related Articles

  • A Monte Carlo study of CO oxidation with oscillations induced by site blocking. Jansen, A. P. J.; Nieminen, R. M. // Journal of Chemical Physics;2/1/1997, Vol. 106 Issue 5, p2038 

    Shows that introduction of an additional adsorbate with appropriate adsorption and desorption rates leads to sustained oscillations in the carbon monoxide oxidation on a catalytic surface. Computational details; Relation between the fraction of vacant sites and X coverage during simulation;...

  • Carbon monoxide–oxygen interaction on the Pt(111) surface: An electron stimulated desorption ion angular distribution (ESDIAD) study. Szabó, A.; Kiskinova, M.; Yates, J. T. // Journal of Chemical Physics;4/15/1989, Vol. 90 Issue 8, p4604 

    CO adsorption on the p(2×2)O–Pt(111) surface was studied by the digital ESDIAD (electron stimulated desorption ion angular distribution) method in combination with TPD, LEED and work function measurements. Three ESD products were detected: CO+ , O+ and metastable CO. The ESDIAD...

  • Calorimetric heats for CO and oxygen adsorption and for the catalytic CO oxidation reaction on... Yeo, Y. Y.; Vattuone, L. // Journal of Chemical Physics;1/1/1997, Vol. 106 Issue 1, p392 

    Investigates the heats of adsorption of carbon monoxide (CO) and oxygen and the reaction heats for the CO oxidation process on platinum surfaces through a single crystal adsorption calorimetry. Microcalorimetric results for CO adsorption; Initial sticking probability; Energy calculation.

  • Effect of the Electronic Structure of a Substrate on the Photoinduced Behavior of Adsorbed NO and CO Molecules. Magkoev, T. T.; Murata, Y. // Technical Physics;Jun2002, Vol. 47 Issue 6, p752 

    Photoprocesses in systems produced by adsorption of NO and CO molecules on the Pt(111) and Ni(111) surfaces, as well as on the (111) surface of Pt-Ge alloy, is studied by the IR absorption spectroscopy, resonant multiphoton ionization, and UV photoelectron spectroscopy methods. The energy of...

  • Laser-induced molecular desorption from size-selected nickel cluster carbonyl ions: Kinetics of the adsorption–desorption equilibrium. Brechignac, C.; Brechignac, Ph.; Fayet, P.; Saunders, W. A.; Wöste, L. // Journal of Chemical Physics;8/15/1988, Vol. 89 Issue 4, p2419 

    Gas phase reactivity of size-selected nickel cluster ions with carbon monoxide has been studied in a triple quadrupole mass spectrometer. Intensity distributions of the various nickel carbonyl ions are measured. Irradiation with a cw Ar+ laser beam demonstrates that efficient detachment of CO...

  • Predesorption of CO from the sodium chloride (100) surface: Study by the complex coordinate method. Ben Ephraim, A.; Folman, M.; Heidberg, J.; Moiseyev, N. // Journal of Chemical Physics;9/15/1988, Vol. 89 Issue 6, p3840 

    The rotational predesorption resonances of CO adsorbed on NaCl(100) were calculated by the quantum mechanical complex coordinate method, the CO bond length being varied adiabatically. It is shown that the internal vibrational excitation of adsorbed CO by an infrared laser does not have a strong...

  • Electron-impact desorption of metastable particles from CO films.  // Low Temperature Physics;Oct98, Vol. 24 Issue 10, p742 

    Examines the impact of monochromatic low-energy electrons on the desorption of metastable particles (MP) from carbon monoxide films. Comparison with the metastable production from gaseous carbon monoxide; Identification of metastable carbon monoxide; Contribution of electronic excitation to MP...

  • Isotope effect in electron stimulated desorption: The role of internal degrees of freedom in CO desorption from Pt(111). Szabó, András; Yates, John T. // Journal of Chemical Physics;1/1/1995, Vol. 102 Issue 1, p563 

    Electron stimulated desorption (ESD) of CO+, O+, metastable neutral CO*, and ground state neutral CO from the CO/Pt(111) was studied, using isotopic substitution of CO. Four isotopic versions of CO were compared in their desorption behavior. Contrary to the prediction of theoretical models that...

  • Nanopores of carbon nanotubes as practical hydrogen storage media. Sang Soo Han; Hyun Seok Kim; Kyu Sung Han; Jai Young Lee; Hyuck Mo Lee; Jeung Ku Kang; Seong Ihl Woo; van Duin, Adri C. T.; Goddard III, William A. // Applied Physics Letters;11/21/2005, Vol. 87 Issue 21, p213113 

    We report on hydrogen desorption mechanisms in the nanopores of multiwalled carbon nanotubes (MWCNTs). The as-grown MWCNTs show continuous walls that do not provide sites for hydrogen storage under ambient conditions. However, after treating the nanotubes with oxygen plasma to create nanopores...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics