Artículos de revistas
Simulation Of Hydrogen Thermal Desorption From Transition Metals Using A Multiple-site Hopping Model
Registro en:
Surface Science. , v. 317, n. 1-2, p. 275 - 279, 1994.
396028
10.1016/0039-6028(94)90275-5
2-s2.0-0028498701
Autor
Cabrera A.L.
Weinketz S.
Cabrera G.G.
Marshall G.
Institución
Resumen
A model to simulate thermal desorption is described. The model is applicable to systems where adsorbate-adsorbate lateral interactions are negligible and fast recombination occurs, as in the case of hydrogen desorption from transition metal surfaces. Thus, our model uses simple rules to simulate desorption. If two atoms are sitting in neighboring sites, then there is a high probability for the desorption of both to happen. If an atom does not have a neighbor, it will move to adjacent sites, in a random walk, until it finds a neighbor to recombine. The desorption rate plotted as a function of the logarithm of the number of random steps results in perfectly shaped Gaussian curves. Dimensionless curves of the rate versus the logarithm of the number of random steps were obtained for different coverages from 0.1 to 1.0 using this method. These curves are in perfect agreement with calculated curves for second-order desorption arising from the corresponding Polanyi-Wigner differential equation. © 1994. 317 1-2 275 279 Vannice, (1975) J. Catal., 37, p. 449 Ehrlich, (1961) J. Appl. Phys., 32, p. 4 Lapujoulade, Neil, (1972) J. Chem. Phys., 57, p. 3535 King, (1975) Surf. Sci., 47, p. 384 Redhead, (1962) Vacuum, 12, p. 203 Chan, Weinberg, (1978) Appl. Surf. Sci., 1, p. 377 Cabrera, (1990) J. Chem. Phys., 93, p. 2854 Schmidt, (1974) Catal. Rev. Sci. Eng., 9, p. 115 Russell, Jr., Gates, Yates, Jr., (1986) J. Chem. Phys., 85, p. 6792 Wedler, Fisch, Papp, Desorptionsspektren und Adsorptionszustände im System Nickel/Wasserstoff (1970) Berichte der Bunsengesellschaft für physikalische Chemie, 74, p. 186 Christmann, Schober, Ertl, Van Hove, Weinberg, (1979) J. Chem. Phys., 70, p. 4168 Burke, Madix, (1990) Surf. Sci., 237, p. 20 Cabrera, Desorption studies of hydrogen and carbon monoxide from nickel surfaces using thermal desorption spectroscopy (1990) Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 8, p. 3229 Cabrera, (1993) J. Vac. Sci. Technol. A, 11, p. 205 George, DeSantolo, Hall, (1985) Surf. Sci., 159, p. L425 Arena, Deckert, George, (1991) Surf. Sci., 241, p. 369 Fichthorn, Weinberg, (1993) Surf. Sci., 286, p. 139 Kang, Jachimowski, Weinberg, (1990) J. Chem. Phys., 93, p. 1418