Multiscale modeling of reaction and diffusion in Zeolites [Elektronische Ressource] / von Niels Hansen

Multiscale modeling of reaction and diffusion in Zeolites [Elektronische Ressource] / von Niels Hansen

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Multiscale Modeling ofReaction and Diffusion inZeolitesVom Promotionsausschuss derTechnischen Universit¨at Hamburg-Harburgzur Erlangung des akademischen GradesDoktor-Ingenieur (Dr.-Ing.)genehmigte DissertationvonNiels HansenausHamburg20101. Gutachter: Prof. Dr. Dr. h.c. Frerich J. Keil2. Gutachter: Prof. Dr. Andreas Liese3. Gutachter: Prof. Dr. Alexis T. BellTag der mu¨ndlichen Pru¨fung: 23.02.2010AcknowledgmentsThis work has been carried out with the Department of Chemical ReactionEngineering (Prof. Frerich J. Keil) at the Hamburg University of Techno-logy in Germany. The project entailed joint work with the Department ofChemical Engineering (Prof. Alexis T. Bell) at the University of Californiain Berkeley, USA.First of all, I would like to express my gratitude to my supervisors. ToProf. Keil who gave me the possibility to work in this field of research. Hehas been an outstanding advisor and teacher. The faithful atmosphere inthe group as well as the possiblity to carry out part of the work abroad hasbeen a rewarding and enjoyable experience. To Prof. Bell, I am thankful forgiving me the opportunity to work in his group as a visiting scholar and foroffering invaluable assistance, support and guidance.Next I would like to thank Prof. Rajamani Krishna for his advice andthe discussions about modeling multicomponent adsorption and diffusion inzeolites.I am grateful to Prof.

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Multiscale Modeling of
Reaction and Diffusion in
Zeolites
Vom Promotionsausschuss der
Technischen Universit¨at Hamburg-Harburg
zur Erlangung des akademischen Grades
Doktor-Ingenieur (Dr.-Ing.)
genehmigte Dissertation
von
Niels Hansen
aus
Hamburg
20101. Gutachter: Prof. Dr. Dr. h.c. Frerich J. Keil
2. Gutachter: Prof. Dr. Andreas Liese
3. Gutachter: Prof. Dr. Alexis T. Bell
Tag der mu¨ndlichen Pru¨fung: 23.02.2010Acknowledgments
This work has been carried out with the Department of Chemical Reaction
Engineering (Prof. Frerich J. Keil) at the Hamburg University of Techno-
logy in Germany. The project entailed joint work with the Department of
Chemical Engineering (Prof. Alexis T. Bell) at the University of California
in Berkeley, USA.
First of all, I would like to express my gratitude to my supervisors. To
Prof. Keil who gave me the possibility to work in this field of research. He
has been an outstanding advisor and teacher. The faithful atmosphere in
the group as well as the possiblity to carry out part of the work abroad has
been a rewarding and enjoyable experience. To Prof. Bell, I am thankful for
giving me the opportunity to work in his group as a visiting scholar and for
offering invaluable assistance, support and guidance.
Next I would like to thank Prof. Rajamani Krishna for his advice and
the discussions about modeling multicomponent adsorption and diffusion in
zeolites.
I am grateful to Prof. Joachim Sauer for giving me the possibility to visit
his group and for the invaluable support he gave me regarding the quantum
chemical modeling of reactions in zeolites.
I am indebted to many former and current group members in Hamburg
and Berkeley for providing support and assistance. In Hamburg I would like
tothank, inparticular, SvenJakobtorweihenforguidingmyfirststepsinthe
field of molecular simulations, Andreas Heyden for introducing me into the
field of quantum chemical calculations, Nils Zimmermann for support with
Gnuplot and the great time in Berkeley 2008, Till Bru¨ggemann for helping
me with some calculations presented in chapter 8, and Klaus Mandel for
all the computer support. I would also like to thank all other colleagues for
providinganiceandrelaxedworkingenvironment: AchimBartsch,Christina
Laarmann, Aykut Arg¨onu¨l, Denis Chaykin, Diana Khashimova, Kobiljon
Kholmatov, Alexander Rudenko, Diana Tranca, and Hermine Oppelaar.
In Berkeley I would like to thank, in particular, Jason Bronkema, Vladi-
mirGalvita,AndrewBehn,FuatCelik,WillVining,XiaoboZheng,Vladimir
Shapovalov, AnthonyGoodrow, JoeSwisherandMaerianMorrisforsupport
and discussions.
I have also benefited from many discussions with different people at vari-
ous institutions: Prof. Berend Smit, Christian Tuma, Torsten Kerber, Jens
D¨obler, Alexander Hofmann, Stian Svelle, Thomas Dargel, Tom´aˇs Buˇcko,
and Uwe Huniar.ii
For providing computer time the “Norddeutscher Verbund fu¨r Hoch- und
H¨ochstleistungsrechnen” (HLRN) is acknowledged. Special thanks go to
Bernd Kallies for continuous technical support.
I would also like to convey thanks to the German Research Foundation
(DFG) for providing the financial means for this project within the priority
program SPP 1155.
Further, I thank my family for their unconditional support and encour-
agement during the course of the thesis.
Finally, I owe special gratitude to Ines Lu¨hmann for her tremendous pa-
tience and consideration in the most crucial stage of this work.Meinen ElternContents
I Introduction 1
1 Background and scope 3
2 Outline 7
II Molecular modeling 9
3 Electronic structure methods 11
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2 Schr¨odinger equation . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.1 Born-Oppenheimer approximation . . . . . . . . . . . . 13
3.2.2 Variational principle . . . . . . . . . . . . . . . . . . . 15
3.3 Hartree-Fock method . . . . . . . . . . . . . . . . . . . . . . . 15
3.4 Møller-Plesset perturbation theory . . . . . . . . . . . . . . . 18
3.5 Coupled-cluster theory . . . . . . . . . . . . . . . . . . . . . . 19
3.6 Density functional theory. . . . . . . . . . . . . . . . . . . . . 21
3.6.1 Gaussian basis sets . . . . . . . . . . . . . . . . . . . . 24
3.6.2 Plane-wave basis sets . . . . . . . . . . . . . . . . . . . 25
4 Molecular simulation methods 27
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
4.2 Statistical thermodynamics. . . . . . . . . . . . . . . . . . . . 28
4.3 Molecular dynamics simulations . . . . . . . . . . . . . . . . . 30
4.4 Monte Carlo simulations . . . . . . . . . . . . . . . . . . . . . 31
4.4.1 The grand canonical Monte Carlo method . . . . . . . 34vi Contents
5 Rates of elementary reactions 37
III Nitrous oxide decomposition on dinuclear oxy-
gen bridged iron sites in Fe-ZSM-5 39
6 A reaction mechanism for the nitrous oxide decomposition
on dinuclear oxygen bridged iron sites in Fe-ZSM-5 41
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6.2 Computational details . . . . . . . . . . . . . . . . . . . . . . 43
6.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . 47
6.3.1 Formation of dinuclear iron sites . . . . . . . . . . . . . 49
– 2+ –6.3.2 N O decomposition on Z [HOFeOFeOH] Z sites . . . 512
– 2+ –6.3.3 N O decomposition on Z [FeOFe] Z sites . . . . . . . 562
6.3.4 Effect of antiferromagnetic coupling . . . . . . . . . . . 59
6.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
7 Microkinetic modeling of nitrous oxide decomposition on di-
nuclear oxygen bridged iron sites in Fe-ZSM-5 63
7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
7.2 Theoretical methods . . . . . . . . . . . . . . . . . . . . . . . 65
7.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . 67
7.3.1 Effects of water vapor on the catalyst surface and the
apparent rate constant . . . . . . . . . . . . . . . . . . 67
7.3.2 Simulation of temperature-programmed reaction ex-
periments . . . . . . . . . . . . . . . . . . . . . . . . . 70
7.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
IV Alkylation of benzene over H-ZSM-5: A multi-
scale investigation 75
8 Theoretical investigation of benzene alkylation with ethene
over H-ZSM-5 77
8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
8.2 Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
8.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . 84
8.3.1 Reaction mechanism for the T5 cluster . . . . . . . . . 84Contents vii
8.3.2 Reaction mechanism for the T17 cluster . . . . . . . . 87
8.3.3 Reaction mechanism for the T33 cluster . . . . . . . . 90
8.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
9 Analysis of diffusion limitation in the alkylation of benzene
over H-ZSM-5 by combining quantum chemical calculations,
molecular simulations, and a continuum approach 101
9.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
9.2 Continuum approach for diffusion and reaction . . . . . . . . . 104
9.3 Parameterization . . . . . . . . . . . . . . . . . . . . . . . . . 111
9.4 Results and discussion . . . . . . . . . . . . . . . . . . . . . . 117
9.4.1 Intrinsic kinetics . . . . . . . . . . . . . . . . . . . . . 117
9.4.2 Effects of diffusional mass transfer . . . . . . . . . . . . 120
9.4.3 Effectiveness factor . . . . . . . . . . . . . . . . . . . . 125
9.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
9.6 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
10 Reactor simulation of benzene ethylation and ethane dehy-
drogenation catalyzed by ZSM-5: A multiscale approach 131
10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
10.2 Reactor model . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
10.3 Performance of PL and LH models . . . . . . . . . . . . . . . 134
10.4 Dehydrogenation of ethane . . . . . . . . . . . . . . . . . . . . 139
10.5 Parameterization . . . . . . . . . . . . . . . . . . . . . . . . . 141
10.6 Results and discussion . . . . . . . . . . . . . . . . . . . . . . 143
10.6.1 Intrinsic kinetics . . . . . . . . . . . . . . . . . . . . . 143
10.6.2 Effects of diffusion limitation . . . . . . . . . . . . . . 144
10.6.3 Effects of hydrogen removal . . . . . . . . . . . . . . . 145
10.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
10.8 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
11 Quantum chemical modeling of benzene ethylation over H-
ZSM-5 approaching chemical accuracy: A hybrid MP2:DFT
study 149
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
11.2 Computational details . . . . . . . . . . . . . . . . . . . . . . 153viii Contents
11.2.1 DFT calculations applying periodic boundary conditions154
11.2.2 MP2 and DFT cluster calculations . . . . . . . . . . . 155
11.2.3 Complete basis set extrapolation . . . . . . . . . . . . 157
11.2.4 PBE+D//PBE calculations . . . . . . . . . . . . . . . 159
11.2.5 CCSD(T) calculations . . . . . . . . . . . . . . . . . . 159
11.2.6 Calculation of intrinsic rate coefficients . . . . . . . . . 160
11.3 Results and discussion . . . . . . . . . . . . . . . . . . . . . . 160
11.3.1 Adsorption of reactants and products . . . . . . . . . . 160
11.3.2 Reaction steps . . . . . . . . . . . . . . . . . . . . . . . 170
11.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
V Back matter 183
12 Summary 185
Appendices 189
A Supporting information for chapter 7 189
B Supporting information for chapter 9 197
B.1 Simulation methodologies . . . . . . . . . . . . . . . . . . . . 198
B.2 Fitting of adsorption isotherms for C H , C H , and C H in2 4 6 6 8 10
MFI and validation of ideal adsorbed solution theory . . . . . 201
B.3 Extraction of M-S diffusivities from MD simulation data . . . 204
B.4 Derivation of the rate expression for the two-step alkylation . 210
B.5 conversion between simulated rates on MFI and experimental
TMrates on AB-97 . . . . . . . . . . . . . . . . . . . . . . . . . 211
B.6 Program structure for the solution of the diffusion-reaction
equation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
B.7 Additional data illustrating the influence of temperature and
partial pressures on observed macroscopic rate orders . . . . . 213
C Supporting information for chapter 10 215
C.1 Simulation methodologies . . . . . . . . . . . . . . . . . . . . 216
C.2 Fitting of adsorption isotherms for C H and H in MFI . . . 2182 6 2