The fight for a reactive site
Groot, I.M.N.
Citation
Groot, I. M. N. (2009, December 10). The fight for a reactive site. Retrieved from https://hdl.handle.net/1887/14503
Version: Corrected Publisher’s Version
License: Licence agreement concerning inclusion of doctoral thesis in the Institutional Repository of the University of Leiden
Downloaded from: https://hdl.handle.net/1887/14503
Note: To cite this publication please use the final published version (if applicable).
PROEFSCHRIFT
ter verkrijging van
de graad van Doctor aan de Universiteit Leiden,
op gezag van Rector Magnificus prof. mr. P. F. van der Heijden, volgens besluit van het College voor Promoties
te verdedigen op donderdag 10 december 2009 klokke 13.45 uur
door
Irene Monique Nicolette Groot
geboren te Amsterdam in 1980
Promotiecommissie
Promotores: Prof. dr. A. W. Kleyn Prof. dr. G. J. Kroes Co-promotores: Dr. L. B. F. Juurlink
Dr. R. A. Olsen Overige leden: Prof. dr. J. Brouwer
Prof. dr. M. C. van Hemert Prof. dr. M. T. M. Koper Prof. dr. A. C. Luntz Dr. M. Rost
Prof. dr. P. Saalfrank Prof. dr. S. Stolte
The research described in this thesis was partially made possible by financial support from Stichting Fundamenteel Onderzoek der Materie (FOM), which is financially supported by de Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO).
Productie en vormgeving omslag: F&N Boekservice
Voor mama
A scientist in his laboratory is not only a technician: He is also a child placed before natural phenomena which impress him like a fairy tale.
Marie Curie (1867-1934)
Contents
1
Introduction 9
1.1 Heterogeneous catalysis . . . 9
1.2 Reactions of atoms and molecules on surfaces . . . 10
1.3 Dissociative adsorption of H2 on a metal surface . . . 12
1.4 H2 + Ru(0001) and H2 + Pt(S): Background and motivation . . . 13
1.4.1 H2 dissociation on Ru(0001) and CO-precovered Ru(0001) . . . 14
1.4.2 Dissociative adsorption of H2 on stepped platinum . . . 16
1.5 Outline and major results of this thesis . . . 18
1.6 Outlook . . . 21
1.6.1 Hydrogen dissociation on bare Ru(0001) . . . 21
1.6.2 Hydrogen dissociation on CO-precovered Ru(0001) . . . 23
1.6.3 Hydrogen dissociation on stepped platinum . . . 24
2
Experimental set-up and techniques 31
2.1 Ultra-high vacuum set-up . . . 312.2 Molecular beam techniques . . . 33
2.3 Surface science techniques . . . 34
2.3.1 Temperature programmed desorption spectroscopy . . . 34
2.3.2 Low energy electron diffraction . . . 35
2.4 Experimental procedures . . . 36
2.4.1 Time-of-flight spectrometry . . . 36
2.4.2 King and Wells technique . . . 38
3
Calculational methods and approximations 45
3.1 The Born-Oppenheimer approximation . . . 453.2 Density functional theory . . . 46
3.3 Building the potential energy surface . . . 47
3.3.1 Electronic structure calculations . . . 47
3.3.2 Modified Shepard interpolation method . . . 48
3.3.3 Implementation of the MS method in GROW . . . 49
3.4 Quantum dynamical calculations: the time-dependent wave packet method . 50 3.4.1 The initial wave packet . . . 51
3.4.2 Time propagation . . . 52
3.4.3 Asymptotic analysis of the wave packet . . . 52
3.4.4 Optical potential . . . 54
3.4.5 Finite basis representations and discrete variable representations . . . 54 v
vi
3.5 Quasi-classical trajectory calculations . . . 58
3.6 Molecular beam simulation . . . 58
3.7 The CO/Ru(0001) system . . . 60
4
Supersonic molecular beam studies of dissociative adsorption of H
2on Ru(0001) 65
4.1 Introduction . . . 654.2 Experimental apparatus and methods . . . 66
4.3 Results . . . 68
4.4 Discussion . . . 69
4.5 Summary . . . 74
5
A theoretical study of H
2dissociation on ( √ 3 × √ 3)R30
◦CO/Ru(0001) 79
5.1 Introduction . . . 795.2 Theory . . . 81
5.2.1 H2 + CO/Ru(0001) system . . . 81
5.2.2 Electronic structure calculations . . . 81
5.2.3 Locating barriers along different H2 dissociation paths . . . 83
5.2.4 Two-center projected density of states calculations . . . 85
5.3 Results and discussion . . . 85
5.3.1 Barrier heights and locations . . . 85
5.3.2 An energy decomposition and a molecular orbital analysis of the H2 approach to the surface and the subsequent dissociation . . . 90
5.4 Conclusions . . . 95
6
Dynamics of dissociative adsorption of hydrogen on a CO- precovered Ru(0001) surface: A comparison of theoretical and experimental results 101
6.1 Introduction . . . 1016.2 Theory . . . 103
6.2.1 Potential energy surface . . . 103
6.2.2 Quasi-classical trajectory calculations . . . 108
6.2.3 Quantum dynamics calculations . . . 110
6.2.4 Molecular beam simulation . . . 111
6.3 Results and discussion . . . 114
6.4 Conclusions . . . 123
7
Dynamics of hydrogen dissociation on Pt(211) 127
7.1 Introduction . . . 1277.2 Experimental apparatus and methods . . . 128
7.3 Results . . . 129
7.4 Discussion . . . 130
7.5 Summary . . . 133
vii
8
Dynamics of hydrogen dissociation on stepped platinum 137
8.1 Introduction . . . 137
8.2 Experimental apparatus and methods . . . 139
8.3 Results and discussion . . . 140
8.3.1 Reaction mechanisms . . . 140
8.3.2 Modeling reactivity on stepped platinum . . . 147
8.5 Conclusions . . . 150
Nederlandse samenvatting 153
List of publications 157
Curriculum Vitae 159
Nawoord 161
