Transport in Nanoporous Solids [Elektronische Ressource] / Oliver Christian Gobin. Gutachter: Johannes A. Lercher ; Klaus Köhler ; Harald Klein. Betreuer: Johannes A. Lercher

Oliver C. Gobin

Informations

• Publié par: technische_universitat_munchen
• Publié le: 01 janvier 2011
• Nombre de lectures: 29
• Langue: Deutsch
• Poids de l'ouvrage: 10 Mo

Extrait

Technische Universitat Munchen
Lehrstuhl fur Technische Chemie II
Transport in Nanoporous Solids
Oliver Christian Jean-Marie Gobin
Vollst andiger Abdruck der von der Fakult at fur Chemie der Technischen Universit at
Munc hen zur Erlangung des akademischen Grades eines
Doktors der Naturwissenschaften (Dr. rer. nat.)
genehmigten Dissertation.
Vorsitzender: Univ.-Prof. Dr.-Ing. K.-O. Hinrichsen
Prufer der Dissertation:
1. Univ.-Prof. Dr. techn. J. A. Lercher
2. Univ.-Prof. Dr. rer. nat., Dr. rer. nat. habil. K. K ohler
3. Univ.-Prof. Dr.-Ing. H. Klein
Die Dissertation wurde am 30.07.2010 bei der Technischen Universit at Munc hen eingere-
icht und durch die Fakult at fur Chemie am 10.02.2011 angenommen..Everything ows, nothing stands still.
Heraclitus of Ephesus
(535 - 475 BC).Contents
Acknowledgments iv
Symbols vi
Abbreviations x
1 Introduction 1
2 State of the art 3
2.1 Porous materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1 Zeolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.2 Mesoporous materials . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.3 Hierarchical materials . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Fundamentals of sorption equilibria . . . . . . . . . . . . . . . . . . . . . 11
2.2.1 The Langmuir adsorption theory . . . . . . . . . . . . . . . . . . 11
2.2.2 Multilayer . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2.3 Pore volume and pore size distribution . . . . . . . . . . . . . . . 15
2.3 Di usion in nanoporous materials . . . . . . . . . . . . . . . . . . . . . . 18
2.3.1 Fundamentals of di usion . . . . . . . . . . . . . . . . . . . . . . 19
2.3.2 Di usion mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.3.3 Experimental methods to measure sorption kinetics . . . . . . . . 24
3 Di usion Pathways of Benzene, Toluene and p-Xylene in MFI 36
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.2 Experimental section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
3.2.2 Physicochemical characterization . . . . . . . . . . . . . . . . . . 40
3.2.3 Frequency response experiments . . . . . . . . . . . . . . . . . . . 40
3.2.4 Model building . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
3.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
i4 Comparison of the Transport of Aromatic Compounds in Small and Large
MFI Particles 55
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.2 Experimental section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
4.2.2 Physicochemical characterization . . . . . . . . . . . . . . . . . . 57
4.2.3 Frequency response experiments . . . . . . . . . . . . . . . . . . . 58
4.2.4 Numerical simulation of the transport network . . . . . . . . . . . 59
4.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.3.1 Particle size and surface morphology . . . . . . . . . . . . . . . . 59
4.3.2 Transport measurements . . . . . . . . . . . . . . . . . . . . . . . 64
4.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
4.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
5 Role of the surface modi cation on the transport of hexane isomers in ZSM5 78
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
5.2 Experimental section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
5.2.2 Physicochemical characterization . . . . . . . . . . . . . . . . . . 81
5.2.3 Gravimetric sorption and uptake experiments . . . . . . . . . . . 82
5.2.4 Infrared spectoscopy . . . . . . . . . . . . . . . . . . . . . . . . . 82
5.2.5 Calculation of sticking probabilities on zeolites . . . . . . . . . . . 84
5.2.6 Theoretical calculations . . . . . . . . . . . . . . . . . . . . . . . 84
5.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
5.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
5.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
6 Di usion in Circularly Ordered Mesoporous Silica Fibers 100
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
6.2 Experimental section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
6.2.1 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
6.2.2 Physicochemical characterization . . . . . . . . . . . . . . . . . . 102
6.2.3 Gravimetric sorption experiments . . . . . . . . . . . . . . . . . . 103
6.2.4 Frequency response experiments . . . . . . . . . . . . . . . . . . . 103
6.3 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
6.3.1 Characterization results . . . . . . . . . . . . . . . . . . . . . . . 104
6.3.2 Frequency response results . . . . . . . . . . . . . . . . . . . . . . 107
6.4 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
6.5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
ii7 Conclusions 121
References 121
List of Figures 134
List of Tables 139
List of Publications 142
iiiAcknowledgments
Only with the help and support of many people was it possible to nish this thesis. In
the rst part of this dissertation, I would like to thank all the people who contributed to
the success of this thesis.
First of all, I would like to thank Professor Dr. Johannes A. Lercher for giving
me the chance to work in a highly diverse international working group at the Chair of
Technical Chemistry 2 at the Technische Universit at Munc hen. I am deeply grateful for
the supervision and guidance during the work and for the freedom I was given.
I would also like to thank my thesis co-supervisor PD Dr. Andreas Jentys for his
support, guidance, and for the scienti c discussions.
I am grateful to Professor K arger and whole international research group ’Di usion
in Zeolites’ for excellent meetings and stimulating discussions.
I also thank my co-worker Dr. Stephan J. Reitmeier, for the close collaboration we
had during the time of the thesis and for the intense and excellent scienti c discussions.
I wish to thank the whole group of Professor Lercher, for the great atmosphere and
the many hours we spent together during conferences, e.g., in Weimar at the German
catalysis conference. Especially I thank Robin Kolvenbach for excellent discussions about
transport processes, and Michi for all the sh. I also thank all students I supervised in
the last few years.
I thank Professor Dr. Ferdi Schuth, who always allowed me to run special measure-
ments required for the thesis at the Max Planck Institute and for all the things I learned
from him and from and the other members of the MPI during my Diploma thesis.
Finally, I want to thank my parents Marie-Helene Gobin and Axel Schneider for their
invaluable support in everything, and my brother Philippe Schneider.
ivvSymbols and abbreviations
Symbols
Latin symbols
A amplitude
2 1B (m s ) mobility
1c (g mol ) concentration
d (m) diameter
2 1D (m s ) di usion coe cient
1E (kJ mol ) energy
2 1F (m s ) single le mobility
3 1F (m s ) ow rate
1G (kJ mol ) free energy
h (m) pitch
1H (kJ mol ) heat of adsorption
2I (kg m ) moment of inertia
1J (mol s ) molar ux
1k (s ) rate constant
K (-) Langmuir or BET equilibrium constant
K (-) Henry constantH
K (-) FR constantFR
L (m) characteristic length
L (-) ZLC constant
1M (g mol ) molar mass
n (-) index
n (-) structural order
n (mol) amount adsorbed
1 23 1N mol avogados number: N = 6:022 10 molA A
P;p (bar) pressure
1q (g mol ) adsorbed phase concentration
q (-) partition function
q (-) rootsn
r m radius
R;r (-) rate
1 1R (J mol K ) molar gas constant
vi