JCP Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

You Tube Flickr Twitter UniPHY Group iResearch App Facebook

Journal of Chemical Physics / Volume 132 / Issue 14 / ARTICLES / Surfaces, Interfaces, and Materials

J. Chem. Phys. 132, 144704 (2010); http://dx.doi.org/10.1063/1.3378278 (12 pages)

A theoretical study of H2 dissociation on (math×math)R30°CO/Ru(0001)

I. M. N. Groot1,2, J. C. Juanes-Marcos1, R. A. Olsen1,3, and G. J. Kroes1

1Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
2FOM Institute for Plasma Physics Rijnhuizen, P.O. Box 1207, 3430 BE Nieuwegein, The Netherlands
3Akershus University College, P.O. Box 423, N-2001 Lillestrøm, Norway

View MapView Map

(Received 16 June 2009; accepted 25 February 2010; published online 13 April 2010)

We have studied the influence of preadsorbed CO on the dissociative adsorption of H2 on Ru(0001) with density functional theory calculations. For a coverage of 1/3 ML CO, we investigated different possible reaction paths for hydrogen dissociation using nudged elastic band and adaptive nudged elastic band calculations. One reaction path was studied in detail through an energy decomposition and molecular orbital type of analysis. The minimum barrier for H2 dissociation is found to be 0.29 eV. At the barrier the H–H bond is hardly stretched. Behind this barrier a molecular chemisorption minimum is present. Next, the molecule overcomes a second barrier, with a second local chemisorption minimum behind it. To finally dissociate to chemisorbed atoms, the molecule has to overcome a third barrier. To move along the reaction path from reactants to products, the hydrogen molecule needs to rotate, and to significantly change its center-of-mass position. The procedure of mapping out reaction paths for H2 reacting on low-index surfaces of bare metals (computing two-dimensional elbow plots for fixed impact high-symmetry sites and H2 orientations parallel to the surface) does not work for H2+CO/Ru. The first barrier in the path is recovered, but the features of the subsequent stretch to the dissociative chemisorption minimum are not captured, because the molecule is not allowed to change its center-of-mass position or to rotate. The dissociative chemisorption of H2 on CO/Ru(0001) is endoergic, in contrast to the case of H2 on bare Ru(0001). The zero-point energy corrected energies of molecularly and dissociatively chemisorbed H2 are very close, suggesting that it may be possible to detect molecularly chemisorbed H2 on (math×math)R30°CO/Ru(0001). The presence of CO on the surface increases the barrier height to dissociation compared with bare Ru(0001). Based on an energy decomposition and molecular orbital analysis we attribute the increase in the barrier height mainly to an occupied-occupied interaction between the bonding H2 σg orbital and the (surface-hybridized) CO 1π orbitals, i.e., to site blocking. There is a small repulsive contribution to the barrier from the interaction between the H2 molecule and the Ru part of the CO covered Ru surface, but it is smaller than one might expect based on the calculations of H2 interacting with a clean Ru surface, and on calculations of H2 interacting with the CO overlayer only. Actually, the analysis suggests that the Ru surface as a subsystem is (slightly) more reactive for the reaction path studied with CO preadsorbed on it than without it. Thus, the results indicate that the influence of CO on H2 dissociation on Ru is not only a simple site-blocking effect, the electronic structure of the underlying Ru is changed.

© 2010 American Institute of Physics

Article Outline

  1. INTRODUCTION
  2. THEORY
    1. H2+CO/Ru(0001) system
    2. Electronic structure calculations
    3. Locating barriers along different H2 dissociation paths
    4. Two-center projected density of states calculations
  3. RESULTS AND DISCUSSION
    1. Barrier heights and locations
    2. An energy decomposition and a molecular orbital analysis of the H2 approach to the surface and the subsequent dissociation
  4. CONCLUSIONS

RELATED DATABASES

To view database links for this article, you need to log in.

KEYWORDS and PACS

Keywords

adsorbed layers, adsorption, band structure, carbon compounds, catalysis, chemisorption, density functional theory, dissociation, hydrogen, orbital calculations, reaction kinetics theory, ruthenium

PACS

  • 82.30.Lp

    Decomposition reactions (pyrolysis, dissociation, and fragmentation)

  • 82.65.+r

    Surface and interface chemistry; heterogeneous catalysis at surfaces

  • 73.20.Hb

    Impurity and defect levels; energy states of adsorbed species

  • 71.15.Mb

    Density functional theory, local density approximation, gradient and other corrections

  • 68.43.Mn

    Adsorption kinetics

  • 82.20.Db

    Transition state theory and statistical theories of rate constants

ARTICLE DATA

Digital Object Identifier
http://dx.doi.org/10.1063/1.3378278

PUBLICATION DATA

ISSN

0021-9606 (print)  
1089-7690 (online)

Publisher

$abstract.society.value is a Member of CrossRef American Institute of Physics

For access to fully linked references, you need to log in.
    T. H. Rod, A. Loggadottir, and J. K. Nørskov, J. Chem. Phys. 112, 5343 (2000)JCPSA6000112000012005343000001.

    J. K. Brown, A. C. Luntz, and P. A. Schultz, J. Chem. Phys. 95, 3767 (1991)JCPSA6000095000005003767000001.

    S. Wilke and M. Scheffler, Phys. Rev. Lett. 76, 3380 (1996).

    C. M. Wei, A. Gross, and M. Scheffler, Phys. Rev. B 57, 15572 (1998).

    A. Gross and M. Scheffler, Phys. Rev. B 61, 8425 (2000).

    E. D. L. Rienks, J. W. Bakker, A. Baraldi, S. A. C. Caribineiro, S. Lizzit, C. J. Weststrate, and B. E. Nieuwenhuys, J. Chem. Phys. 119, 6245 (2003)JCPSA6000119000012006245000001.

    P. J. Feibelman and D. R. Hamann, Phys. Rev. Lett. 52, 61 (1984).

    C. Stampfl and M. Scheffler, Phys. Rev. B 65, 155417 (2002).

    J. S. McEwen and A. Eichler, J. Chem. Phys. 126, 094701 (2007)JCPSA6000126000009094701000001.

    H. Pfnür and D. Menzel, J. Chem. Phys. 79, 2400 (1983)JCPSA6000079000005002400000001.

    J. Braun, K. L. Kostov, G. Witte, and C. Wöll, J. Chem. Phys. 106, 8262 (1997)JCPSA6000106000019008262000001.

    I. M. N. Groot, H. Ueta, M. J. T. C. van der Niet, A. W. Kleyn, and L. B. F. Juurlink, J. Chem. Phys. 127, 244701 (2007)JCPSA6000127000024244701000001.

    J. K. Vincent, R. A. Olsen, G. J. Kroes, M. Luppi, and E. J. Baerends, J. Chem. Phys. 122, 044701 (2005)JCPSA6000122000004044701000001.

    C. H. Mak, A. A. Deckert, and S. M. George, J. Chem. Phys. 89, 5242 (1988)JCPSA6000089000008005242000001.

    R. L. C. Wang, H. J. Kreuzer, P. Jacob, and D. Menzel, J. Chem. Phys. 111, 2115 (1999)JCPSA6000111000005002115000001.

    B. Hammer, L. B. Hansen, and J. K. Nørskov, Phys. Rev. B 59, 7413 (1999).

    J. P. Perdew, J. A. Chevary, S. H. Vosko, K. A. Jackson, M. R. Pederson, D. J. Singh, and C. Fiolhais, Phys. Rev. B 46, 6671 (1992).

    D. Vanderbilt, Phys. Rev. B 41, 7892 (1990).

    H. J. Monkhorst and D. J. Pack, Phys. Rev. B 13, 5188 (1976).

    H. Over, W. Moritz, and G. Ertl, Phys. Rev. Lett. 70, 315 (1993).

    B. Hammer, Y. Morikawa, and J. K. Nørskov, Phys. Rev. Lett. 76, 2141 (1996).

    H. Pfnür, P. Feulner, and D. Menzel, J. Chem. Phys. 79, 4613 (1983)JCPSA6000079000009004613000001.

    G. Henkelman and H. Jónsson, J. Chem. Phys. 113, 9978 (2000)JCPSA6000113000022009978000001.

    K. Svensson, L. Bengtsson, J. Bellman, M. Hassel, M. Persson, and S. Andersson, Phys. Rev. Lett. 83, 124 (1999).

    B. Hammer, Phys. Rev. B 63, 205423 (2001).


For access to citing articles, you need to log in.


Figures (8) Tables (5)

Access to article objects (figures, tables, multimedia) requires a subscription; log in to view available files.
(Access to supplementary files, where available, is free for this journal.)

Access to article objects (figures, tables, multimedia) requires a subscription; log in to view available files.
(Access to supplementary files, where available, is free for this journal.)


Close

Google Calendar

ADVERTISEMENT

Your Recent History Recent History Help

Recently Viewed

  1. A theoretical study of H2 dissociation on (×)R30°CO/Ru(0001)
Go to AIP Home
Copyright © American Institute of Physics
close