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Development of MFI-type zeolite coatings on SiSiC ceramic monoliths for catalytic applications [Elektronische Ressource] = Entwicklung von MFI-Typ-Zeolith-Beschichtungen auf SiSiC keramischen Monolithen für katalytische Anwendungen / vorgelegt von Alessandro Zampieri

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Development of MFI-type Zeolite Coatings on SiSiC Ceramic Monoliths for Catalytic Applications Entwicklung von MFI-Typ Zeolith Beschichtungen auf SiSiC keramischen Monolithen für katalytische Anwendungen Der Technischen Fakultät der Universität Erlangen-Nürnberg zur Erlagung des Grades DOKTOR - INGENIEUR vorgelegt von Alessandro Zampieri Erlangen 2007 Als Dissertation genehmigt von der Technischen Fakultät der Universität Erlangen-Nürnberg Tag der Einreichung: 20.06.07 Tag der Promotion: 12.09.07 Dekan: Prof. Dr. A. Leipertz Berichterstatter: Prof. Dr. W. Schwieger Prof. Dr. P. Greil This PhD work was performed at the Institute of Chemical Reaction Engineering of the Friedrich-Alexander University of Erlangen-Nürnberg in Erlangen (Germany), between May 2002 and December 2006. First of all, I would like to thank Prof. Wilhelm Schwieger, my supervisor and head of the research group, for giving me the chance of conducting this PhD work in his group and for the trust he showed in me. He has always taken care of technical and scientific, as well as of the personal and private life issues of each team member. For me, he has been a guide as supervisor and as man. I also want to thank Prof. Gerhard Emig and Prof.
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Development of MFI-type Zeolite Coatings on SiSiC
Ceramic Monoliths for Catalytic Applications


Entwicklung von MFI-Typ Zeolith Beschichtungen auf SiSiC
keramischen Monolithen für katalytische Anwendungen




Der Technischen Fakultät der
Universität Erlangen-Nürnberg


zur Erlagung des Grades


DOKTOR - INGENIEUR


vorgelegt von


Alessandro Zampieri


Erlangen 2007
































Als Dissertation genehmigt von
der Technischen Fakultät der
Universität Erlangen-Nürnberg


Tag der Einreichung: 20.06.07
Tag der Promotion: 12.09.07
Dekan: Prof. Dr. A. Leipertz
Berichterstatter: Prof. Dr. W. Schwieger
Prof. Dr. P. Greil

This PhD work was performed at the Institute of Chemical Reaction Engineering of the
Friedrich-Alexander University of Erlangen-Nürnberg in Erlangen (Germany), between May
2002 and December 2006. First of all, I would like to thank Prof. Wilhelm Schwieger, my
supervisor and head of the research group, for giving me the chance of conducting this PhD
work in his group and for the trust he showed in me. He has always taken care of technical
and scientific, as well as of the personal and private life issues of each team member. For me,
he has been a guide as supervisor and as man. I also want to thank Prof. Gerhard Emig and
Prof. Peter Wasserscheid for contributing to this result, by perfectly managing the research
facilities of the institute and creating a very interdisciplinary, stimulating and challenging
work environment. Special thanks also go to Prof. Greil (WW3), for making this collaborative
project between the two departments and my research topic possible and for having supported
my work so much during the last four years.

Without the help of those students who conducted their master/bachelor thesis under my
supervision or worked as research assistants, this work would not have been possible.
Therefore, I would like to truly thank the following students, whose important contribution in
my research as well as personal life I will never forget: Stephen Kullman, Alexander
Rudolph, Gajendra Pradhan, Chiriki Suresh, Johanna Baumgartner. My acknowledgment is
also for all the members of the research group, for making every working day so wonderful. I
cannot remember coming to work even one day without motivation, excitement, happiness
and joy. My colleagues made it possible to create such an enjoyable and nice environment
where to work: for this reason I truly thank them. During my years here, I really felt like
being in a family more than in a work group. I am especially indebted to Selvam Thangaraj
and Godwin Mabande for their guidance in the early stages of my PhD and for the countless
discussions and the fruitful collaboration. I am also very grateful to Jürgen Bauer, Saiprasath
Gopalakrishna and Abijeet Avhale for their constant help and substantial contributions to my
work. These people have really meant a lot to me as colleagues and as friends. They
contributed in a very significant way to my professional and personal development. My
thanks also go to Hasan Baser for the ever-kind support and to Dr. André Unger for
introducing me to the technical and practical aspects of laboratory setup handling and
building. I would also like to thank Dr. Ralph Herrmann for his advice and assistance in any
situation, and Dr. Franziska Scheffler for her guidance and advice, especially at the beginning
of my work. I am fully and gratefully indebted to Dr. Heino Sieber (WW3, University
Erlangen-Nürnberg) for the help he gave in the development of my PhD research project.
Without him, most of the ideas and projects involved in my research would have never
become concrete results. I would also like to thank Dr. Jürgen Zeschky and Dr. Tobias Fey,
from WW3 for their indispensable help with the preparation of the ceramic supports,
particularly in the early stages of the project.

I would also like to acknowledge some other colleagues at the Chemical Reaction
Engineering Institute, whom I asked for advice or help during my PhD: Prof. Dr. Nadejda
Popovska, Dr. Andreas Schneider, Hanadi Ghanem, Katia Michkova and Dr. Hannsjörg
Freund.

At this point, I would like to acknowledge the indispensable contribution of the CRT staff.
Special thanks, for their kindness and great help, go to Michael Schmacks and Achim
Mannke, members of the mechanical workshop, and Walter Fischer and Gerhard Dommer,
from the computer and electrical workshops respectively. Their contribution has been vital for
the development of the catalytic reactor setup for my studies. They made sure I always had
the necessary support to carry out my research work as efficiently as possible. A special thank goes to Helmut Gerhard for his unbelievable support and kindness, and for his precious
assistance, essential guidance and indispensable help with the commissioning and trouble-
shooting of the reactor setup and the ammonia TPD apparatus. He has really taught me a lot,
being for me an incomparable teacher: for this reasons I feel fully indebted to him. I would
also like to thank Mrs. Regine Müller for the huge amount of time she dedicated to analysing
my samples by XRD and ICP-OES and for offering constant support in the activities of the
“Zeolite Lab”, making sure that I always had what I needed on time, in order to work
efficiently and productively. The work of Peter Widlok and Siegfried Smolny for the nitrogen
adsorption measurements is also greatly acknowledged. Many thanks go to Ms. Eva Springer,
Ana Strelec and Alena Rybar (WW3) for their indispensable help in the characterisation of
the samples by SEM. Karl Nigge, Marcus Hirschmann and Harald Wiehler have been very
helpful in the introduction to the micro-Computed Tomography setup: I would like to thank
them for the technical assistance during the measurements. At the end, I would like
acknowledge Ms. Michelle Menuet, Ms. Hildegundis Hajas, Ms. Petra Singer and Ms. Petra
Weber, from the secretary office, for their extreme kindness and very efficient support in
many administrative issues.

I am also greatly appreciative of the useful advice of Prof. Paolo Colombo (University of
Padova, Italy), during my time in Erlangen. He has firstly been my supervisor during my
master thesis and later on a colleague and a friend, whose valuable suggestions have always
played a major role in my professional as well as private life. For the enthusiastic interest and
feedback shown towards my research work, I would also like to thank Prof. Brauerlein. One
special mention goes to Dr. U. Müller (BASF) for his encouragement and for the fruitful and
interesting discussions. More than once, he has given me the unique chance to visit his group
and labs, providing me with extensive information regarding R&D activities in huge chemical
plants such as BASF.

To my whole family goes my deepest gratitude for the never-ending support during my PhD
studies in Germany. In particular, I need to thank my parents and my brother, who at first,
made it possible to be at this point of my life. Thanks to them for never letting me alone nor
making me feel the distance from what I still call „Home“. One particular mention goes to my
grandmother, whose moral support has valuably contributed to the achievement of this result:
I deeply wish she could be here to assist me once more, like she did every day of her life. It is
too late for her to see it, but I finally maintained the promised I made to her.

Special thanks go to the person who gave me the most unwavering, continuous and ceaseless
support and whose help, suggestions and contribution made it possible for me to be here
today, writing the last lines of my PhD. Thank you, Simran, so much for your patience,
understanding, perseverance, sacrifice and love during this very hard and busy time of my
life.

Finally, I would like to acknowledge every person who, with his/her wanted or unwanted
contribution, made me reach this goal and this point of my life where I am, happy for all I
accomplished, all I have and all which is coming next.


Erlangen, June 2007 Alessandro Zampieri















The eternal Dream
Is borne on the wings of ageless Light
that rends the veil of the vague
and goes across time
weaving ceaseless patterns of Being.

The mystery remains dumb,
the meaning of this pilgrimage,
the endless adventure of existence
whose rush along the sky
flames up into innumerable rings of paths,
till at last knowledge gleams out from the dusk
in the infinity of human spirit,
and in that dim lighted dawn
she speechlessly gazes through the break in the mist
at the vision of Life and Love
rising from the tumult of profound pain and joy.



Gurudev Rabindranath Tagore
Santiniketan, India (1929)









to my family and to Simran
























































Table of contents

1 Motivation 1
2 Fundamentals and state of the art 9
2.1 Zeolites 9
2.1.1 History and fundamentals 9
2.1.2 Definition 9
2.1.3 Nomenclature 10
2.1.4 Structure 11
2.1.5 Chemistry 13
2.1.6 Properties 14
2.1.7 Zeolite crystallisation 14
2.1.8 Post-synthesis treatment 17
2.1.8.1 Preparation of the H-form 17
2.1.8.2 Preparatioe metal-form 18
2.1.8.3 Impregnation 18
2.1.8.4 Thermal and hydrothermal treatments 19
2.1.8.5 Delamination 19
2.1.8.6 Silanation 19
2.1.8.7 Acid treatment 19
2.1.8.8 Alkaline treatments 20
2.1.9 Applications 21
2.1.10 Zeolite and catalysis 22
2.1.10.1 Shape-selectivity 23
2.1.10.2 Acidity 24
2.1.10.3 Diffusion 27
2.1.10.4 Crystal size 28
2.1.11 MFI-type zeolite 28
2.1.11.1 Framework structure 29
2.1.11.2 Chemistry 29
2.1.11.3 Thermal stability / behaviour 30
2.1.11.4 Synthesis 30
2.1.11.5 Applications 31
2.2 Zeolite coatings and composites 33
2.2.1 Definition and terms 33
2.2.2 Coating techniques 34
2.2.2.1 Ex-situ techniques 35
2.2.2.1.1 Dip-/Slurry-coating 35
2.2.2.1.2 Spin-coating 37
2.2.2.1.3 Self-assemblyvia chemical linkers 38
2.2.2.1.4 Layer-by-Layer deposition 40
2.2.2.1.5 Electrophoretic deposition 41
2.2.2.1.6 Langmuir-Blodgett 42
2.2.2.1.7 Pulsed-Laser Deposition 44
2.2.2.2 In-situ techniques 44
2.2.2.2.1 Conventional direct hydrothermal synthesis 46
2.2.2.2.2 Dry- and wet-gel conversion (solid-state transformation) 47
2.2.2.2.3 Seeding and secondary crystal growth 49
2.2.2.2.4 Support Self-Transformation 50 2.2.3 Summary 51
2.2.4 Coating adhesion 52
2.2.5 Applications 52
2.3 Structured reactors: the monolithic catalyst 54
2.3.1 Introduction 54
2.3.2 Definition and terminology 54
2.3.3 Materials, structures and technology 55
2.3.4 Monoliths and catalysis 58
2.3.4.1 Hierarchy concept 59
2.3.4.2 Monolithic catalysts 59
2.3.4.3 Coatings of monoliths with an active phase (catalyst) 60
2.3.4.4 Catalytic reactors: monoliths vs. fixed-bed catalyst packings 63
2.3.4.5 Monoliths and technical applications 66
2.3.5 Monoliths and zeolite 69
2.3.6 Summary 79
2.4 Alternative cellular ceramic monoliths 81
2.4.1 SiSiC composites 81
2.4.1.1 Biomorphous materials 81
2.4.1.2 Ceramic materials via carbon infiltration with metals 82
2.4.1.3 Bio- and bio-derived templates 83
2.4.1.4 Biomorphous SiC and SiSiC ceramics 86
2.5 Environmental catalysis and the role of zeolites 91
2.5.1 N O emission abatement 91 2
2.5.1.1 Nitrous oxide 91
2.5.1.2 Sources of nitrous oxide emissions 92
2.5.1.3 Methods for the reduction of nitrous oxide emissions 93
2.5.1.4 Catalysts for the N O decomposition and Selective-Catalytic-Reduction 95 2
2.5.1.5 Fe-zeolite for the N O abatement: active sites and reaction mechanism 98 2
2.5.1.6 Technical processes: production of N O and abatement technologies 102 2
2.5.1.7 N O SCR and monolithic catalysts 107 2
2.6 Conclusions 108
3 Experimental 113
3.1 Sample preparation 114
3.1.1 SiSiC ceramic monoliths preparation 114
3.1.2 MFI-type zeolite crystallisation onto SiSiC substrates: SST method 115
3.1.3 Post-synthesis treatment 117
3.1.4 Fe-ZSM-5 zeolite powder 118
3.1.5 Alkaline treatment of ZSM-5 zeolite powder 118
3.1.6 Dip-coating of ZSM-5 zeolite on SiSiC monoliths 118
3.1.7 Hydrothermal crystallisation of ZSM-5 on SiSiC monoliths 119
3.1.8 Seed-assisted secondary crystal growth of ZSM-5 on SiSiC monoliths 119
3.2 Sample characterisation 121
3.2.1 Physicochemical characterisation 121
3.2.2 Catalytic tests 124
3.2.2.1 n-Hexane cracking 124
3.2.2.2 Nitrous oxide decomposition 127
3.2.2.3 Ni Selective-Catalytic-Reduction with propane 128
3.2.2.3.1 Reactant Dosing and Piping 129
3.2.2.3.2 Reactor Chamber 131
3.2.2.3.3 Analytics 135
3.2.2.3.4 Ideal behaviour of the reactor 137
3.2.2.3.5 Catalytic test conditions and data evaluation 138
3.3 Summary 140
4 Results and discussion 143
4.1 SiSiC ceramic monoliths 145
4.1.1 Rattan-derived SiSiC monoliths 145
4.1.2 One-side corrugated cardboard-derived SiSiC monoliths 151
4.1.3 Conclusions 154
4.2 Functionalisation of SiSiC ceramic monoliths with MFI-type zeolite 155
4.2.1 Si dissolution from the SiSiC substrate 156
4.2.2 Si-sources for the synthesis of MFI-type zeolite 158
4.2.3 MFI-type zeolite coatings on Rattan-derived SiSiC ceramics via SST 160
4.2.3.1 Variation of the template amount 161
4.2.3.2 Variation of the synthesis time 163
4.2.3.3 Variation of the Al content 176
4.2.3.4 Variation of the synthesis temperature 181
4.2.3.5 Variation of the NaOH concentration 185
4.2.3.6 Simultaneous variation of TPABr, NaOH and water amount 188
4.2.3.7 Conclusion on Rattan-derived SiSiC/zeolite composites 192
4.2.4 MFI-type zeolite coatings on cardboard-derived SiSiC ceramics via SST 193
4.2.4.1 Preliminary experiments 193
4.2.4.2 Reproducibility 197
4.2.4.3 Synthesis temperature 198
4.2.4.4 Template concentration and type 199
4.2.4.5 Influence of Al concentration and Al precursor in the synthesis mixture 200
4.2.4.6 Solution-to-support ratio 203
4.2.4.7 Fluoride media 204
4.2.4.8 Use of MFI-type zeolite seeds 205
4.2.4.9 Optimisation of the zeolite loading and monolith activity 206
4.2.4.10 Zeolite coating techniques 211
4.2.4.11 Zeoating adherence 213
4.2.4.12 Conclusions: SST zeolite coatings on cardboard-derived SiSiC monoliths 213
4.2.4.13 A model theory for the SST crystallisation mechanism 214
4.2.5 Zeolite coatings on alternative monoliths via Support Self-Transformation 221
4.2.6 Alkaline treatment of zeolites and SST zeolite coatings 225
4.2.7 Fe-ZSM-5 preparation 230
4.2.8 Fe-exchanged SST monoliths for the N O Selective-Catalytic-Reduction 232 2
4.2.9 Fe-ZSM-5 wash-coats on ceramic substrates 237
4.3 Catalytic tests 241
4.3.1 n-hexane cracking 241
4.3.2 Catalytic N O decomposition 243 2
4.3.3 N O Selective-Catalytic-Reduction with C H 248 2 3 8
4.3.3.1 Ideal behaviour of the reactor setup 249
4.3.3.1.1 Ideal isothermal temperature profile 249
4.3.3.1.2 Empty tube test 250
4.3.3.1.3 Ideal plug-flow reactor 250
4.3.3.1.4 Pressure-drop 252
4.3.3.2 Fe-ZSM-5 Pellets 252
4.3.3.3 Fe-ZSM-5 dip-coated SiSiC monolith 260
4.3.3.4 Fe-ZSM-5 coated SiSiC monolith via Support Self-Transformation 264 4.3.3.5 Fe-ZSM-5 dip-coated cordierite honeycomb 273
4.3.3.6 Comparison of the catalysts: structure and coating type 274
4.3.3.7 Conclusions 290
5 Conclusions 292
5.1 SiSiC ceramic monoliths preparation 293
5.2 SST-type zeolite coatings on SiSiC ceramic monoliths 294
5.3 Monolithic reactor for the N O SCR with C H 296 2 3 8
5.4 Outlook 298
References 307
Appendix 333
List of symbols and abbreviations 399

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