TITLE

Direct dissociative chemisorption of propane on Ir(110)

AUTHOR(S)
Kelly, D.; Weinberg, W. H.
PUB. DATE
December 1996
SOURCE
Journal of Chemical Physics;12/22/1996, Vol. 105 Issue 24, p11313
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
We have employed molecular beam techniques to investigate the initial probability of direct dissociative chemisorption, P[SUBd], and the intrinsic trapping probability,&xgr;, of C[SUB3]H[SUB8], C[SUB3]D[SUB8] , and (CH[SUB3])[SUB2]CD[SUB2] on Ir(110) as a function of beam translational energy, E[SUBi], from 1.5 to 59 kcal/mol. For C[SUB3]H[SUB8] and (CH[SUB3])[SUB2]CD[SUB2], a measurable (⩾0.02) initial probability of direct dissociative chemisorption is observed above a beam energy of approximately 7 kcal/mol. For C[SUB3]D[SUB8] this energy is roughly 10 kcal/mol. Above these energies the initial probability of direct chemisorption of each of the isotopomers of propane increases nearly linearly with E[SUBi], approaching a value of approximately P[SUBd] = 0.48 at E[SUBi] = 52 kcal/mol for C[SUB3]H[SUB8] and (CH[SUB3])[SUB2]CD[SUB2], and P[SUBd] = 0.44 at E[SUBi] = 59 kcal/mol for C[SUB3]D[SUB8]. This kinetic isotope effect for the direct chemisorption of C[SUB3]D[SUB8] relative to C[SUB3]H[SUB8] is smaller than that expected for a mechanism of H (or D) abstraction by tunneling through an Eckart barrier, suggesting a contribution of C-C bond cleavage to direct chemisorption. The lack of a kinetic isotope effect for the direct chemisorption of (CH[SUB3])[SUB2]CD[SUB2] relative to C[SUB3]H[SUB8] indicates that 1° C-H bond cleavage dominates over 2° C-H bond cleavage during the direct chemisorption of propane on Ir(110). The trapping behavior of each of these isotopomers of propane is approximately identical as a function of E[SUBi], with &xgr; > 0.9 at E[SUBi] = 1.5 kcal/mol, &xgr; = 0.3 at E[SUBi] = 20 kcal/mol, and &xgr; < 0.1 above E[SUBi] = 40 kcal/mol.
ACCESSION #
9815298

 

Related Articles

  • Isotope effects in trapping-mediated chemisorption of ethane and propane on Ir(110). Kelly, D.; Weinberg, W. H. // Journal of Chemical Physics;9/1/1996, Vol. 105 Issue 9, p3789 

    We compare here recent results of molecular beam investigations of the initial probability of trapping-mediated C–H and C–D bond cleavage of C2H6, C2D6, C3H8, and C3D8 on Ir(110) at low beam translational energy and surface temperatures, TS, from 85 to 800 K. Each of these systems...

  • Effect of translational energy on the molecular chemisorption of CO on Ni(111): Implications for the dynamics of the chemisorption process. Tang, S. L.; Beckerle, J. D.; Lee, M. B.; Ceyer, S. T. // Journal of Chemical Physics;6/1/1986, Vol. 84 Issue 11, p6488 

    The effect of translational energy on the molecular chemisorption of CO on a Ni(111) surface is used as a probe of the dynamics of the adsorption process. Initial adsorption probabilities, apparent saturation coverages, spatially resolved Auger coverage profiles, and high resolution electron...

  • Trapping-mediated dissociative chemisorption of ethane on Ir(110)-(1×2). Mullins, C. B.; Weinberg, W. H. // Journal of Chemical Physics;4/1/1990, Vol. 92 Issue 7, p4508 

    Evidence is presented to support a trapping-mediated dissociative chemisorption mechanism for ethane interacting with an Ir(110)-(1×2) surface. The data were obtained from supersonic molecular-beam measurements with an incident kinetic energy Ei ranging between 1.2 and 24.1 kcal/mol, a...

  • Effect of incidence kinetic energy and surface coverage on the dissociative chemisorption of oxygen on W(110). Rettner, C. T.; DeLouise, L. A.; Auerbach, D. J. // Journal of Chemical Physics;7/15/1986, Vol. 85 Issue 2, p1131 

    The dissociative chemisorption of oxygen on W(110) has been studied using molecular beam techniques. Chemisorption probabilities have been measured as a function of incidence angle, θi, and kinetic energy, Ei, and of surface coverage and temperature. In addition, angular scattering...

  • Supersonic molecular beam studies of the dissociative chemisorption of GeH4 and Ge2H6 on the Ge(100) and Ge(111) surfaces. Jones, M. E.; Roadman, S. E.; Lam, A. M.; Eres, G.; Engstrom, J. R. // Journal of Chemical Physics;10/22/1996, Vol. 105 Issue 16, p7140 

    The reaction probabilities of GeH4 and Ge2H6 on the Ge(100) and Ge(111) surfaces have been measured as a function of substrate temperature, incident kinetic energy, and angle of incidence employing supersonic molecular beam scattering techniques. At sufficiently large incident kinetic energies...

  • Probing the (dual) repulsive wall in the interaction of O2, N2, and Ar with the Ag(111) surface. Raukema, Age; Dirksen, Ruud J.; Kleyn, Aart W. // Journal of Chemical Physics;10/8/1995, Vol. 103 Issue 14, p6217 

    We have performed molecular beam scattering experiments of O2, N2, and Ar from the Ag(111) surface in the translational energy regime from 0.2 to 2.6 eV and at surface temperatures of 600 and 150 K. The experiments were carried out to probe the repulsive part in the particle–surface...

  • The optical and optical/Stark spectrum of iridium monocarbide and mononitride. Marr, A. J.; Flores, M. E.; Steimle, T. C. // Journal of Chemical Physics;6/1/1996, Vol. 104 Issue 21, p8183 

    Supersonic molecular beam samples of iridium monocarbide IrC and iridium mononitride IrN were generated using a laser ablation/reaction source and characterized using high resolution (Δν<30 MHz FWHM) laser induced fluorescence spectroscopy. This is the first identification of gaseous IrN....

  • Growth and structure of IrSi3 on Si(111). Lange, Davis A.; Gibson, Gary A.; Falco, Charles M. // Journal of Applied Physics;3/15/1994, Vol. 75 Issue 6, p2917 

    Focuses on a study which observed the growth and structure of iridium silicon[sub3] films on silicon by molecular-beam epitaxy (MBE). Formation of iridium silicon[sub3] by MBE codeposition; Effect of deposition temperature on epitaxy of codeposited iridium silicon[sub3]; Analysis of the surface...

  • First high resolution analysis of the absorption spectrum of propane in the 6.7 μm to 7.5 μm spectral region. Flaud, J.-M.; Lafferty, W. J.; Herman, M. // Journal of Chemical Physics;6/1/2001, Vol. 114 Issue 21 

    The rotational structure of the v[sub 19] (CH[sub 2[sup -]] wagging, A-type band), v[sub 18] (CH[sub 3[sup -]] s-deformation, A-type band), v[sub 24] (CH[sub 3[sup -]] d-deformation, C-type band), and v[sub 4] (CH[sub 3[sup -]] d-deformation, B-type band) vibrational fundamentals of propane,...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

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

Try another library?
Sign out of this library

Other Topics