Synthetic approaches utilizing zeosils [Elektronische Ressource] : inorganic insertion compounds and hierarchical pore structures / von Geanina Ramona Nechifor

Geanina Ramona Nechifor

Informations

• Publié par: gottfried_wilhelm_leibniz_universitat_hannover
• Publié le: 01 janvier 2005
• Nombre de lectures: 24
• Langue: English
• Poids de l'ouvrage: 2 Mo

Extrait

Synthetic Approaches Utilizing Zeosils:
Inorganic Insertion Compounds and
Hierarchical Pore Structures


Von der Naturwissenschaftlichen Fakultät der Universität Hannover
zur Erlangung des Grades

Doktorin der Naturwissenschaften
– Dr. rer. nat. –

genehmigte Dissertation
von

Dipl.-Ing. Geanina Ramona Nechifor
geboren am 22. Dezember 1976
in Resita (Rumänien)


2005
1




















Referent: Prof. Dr. Peter Behrens
Korreferent: Prof. Dr. Jürgen Caro
Tag der Promotion: 20. Juli 2005
2
Erklärung



Hiermit erkläre ich gemäß §6.b der gemeinsamen Ordnung der naturwissenschaftlichen
Fachbereiche der Universität Hannover für die Promotion zum „Doktor der
Naturwissenschaften“, dass ich die Dissertation unter dem Titel „Synthetic Approaches
Utilizing Zeosils: Inorganic Insertion Compounds and Hierarchical Pore Structures“ selbst
verfasst und die benutzten Hilfsmittel und Quellen vollständig angegeben habe.

Gemäß §6.c erkläre ich weiterhin, dass diese Dissertation noch nicht veröffentlicht und in
keiner Form als Prüfungsarbeit verwendet wurde.



Hannover, den 18.05.2005


Dipl-Ing. Geanina Ramona Nechifor

3
Acknowledgements


And now, that I reached the end, I would like to acknowledge those people, family, friends and
colleagues, that stood by me in these last three years. It is a tradition to do so, even if the words
will never be able to express my real gratitude to them.

Let me start by first thanking my family, who even if never completely understood what I’m
doing so far from them, supported me always and believed I’m going to make it.
To my husband, Marcello, thanks for your permanent encouragement and for your support
during all these years. I cannot tell you how happy I am to have you by my side.

Prof. Behrens, thank you for giving me the chance to enter your group and together with this,
into the captivating world of zeolites, so new for me. Thank you also for all our discussions
(never giving up talking English to me) and for the opportunity to participate to many
conferences that allowed me to find out more about the world of research.

Special thanks to Birgit and Songül, so good friends from the beginning. You showed me the
other side of Hannover, the one outside work. And thanks Birgit for always finding the time for
my TGA measurements.

To all my colleagues, past and present, Dr. Andreas Schneider, Dr. Michael Wiebcke, Olaf,
Clemens, Hans, Stephan (all doctors now), Carsten, Petra who welcomed me in Germany and
made me feel as home. I will always remember our badminton evenings!
Special thank to Ralph and Monika, who shared with me their experience with zeosils.
But thanks also to the younger colleagues, Stefan, Katrin, Boris, Ilka, Michael, Kay, who
brought fresh ideas and enthusiasm to our group.
I wish you all the best.

I would like to express my acknowledgment to the people in Leuven, who hosted me in their
labs for three months. Thank to Prof. Martens, who accepted me there and gave me the
opportunity to learn about zeogrids and zeotiles.
My gratitude to Prof. Cristine Kirschhock, for always finding time for me and for our
discussions.
I
Special thanks to Sebastien and Alex, to Bogdan, Steliana, Roxana, Raluca, Angelica and
Andrei, who guided me through the “labyrinth” of the Institute from Leuven.
Best wishes to you all.

With regard to the Raman and TGA experiments, I am very grateful to PD Dr. Claus Rüscher
from the Institute of Mineralogy, Hannover; and to Sonja Locmelis from AK Binnewies, thanks
for sharing with me the “strategy” of melting quartz-ampoules.

Last but not least I would like to thank the Graduate Program sponsored by the State of
Niedersachsen for bringing together people of so many nationalities and creating this
multicultural experience. Kalpana, Andrea, Adrian, Paras, Marc, Rana, Muayad, Murshed,
Nisath, Ling, Alexander, to all of you, my best wishes for the future.
II
Table of contents


Abstract VI
Kurzzusammenfassung IX

1. INTRODUCTION 1

2. GENERAL CONSIDERATIONS 3
2.1. Porous inorganic materials 3
2.2. Synthesis of microporous materials 6
2.2.1. Hydrothermal synthesis of zeosils
2.2.2. Synthesis of zeogrids and zeotiles from clear solution 8
Formation mechanism 9
2.3. Insertion compounds 12
2.4. Structures of host materials 14
2.5. Guest compounds for insertion experiments 17
2.5.1. Iodine 17
2.5.2. Selenium 20
2.5.3. Mercury(II) halides 24
2.5.4. Gold(III) chloride 29
2.6. Azo-dyes 31

3. EXPERIMENTAL 34
3.1. Insertion compounds 34
3.1.1. Synthesis and characterization of host materials 35
A. Synthesis of zeosils 35
Silicalite-1 36
ITQ-4 38
SSZ-24 39
CIT-5 41
III
UTD-1 43
B. Characterization of zeosils 45
3.1.2. Insertion experiments 52
3.2. Zeodyes synthesis from clear solution 57
3.2.1. Preparation of Silicalite-1 nanoslab suspension 57
3.2.2. Synthesis of zeodyes
3.2.3. Calcination of 60
3.3. Characterization techniques 62
X-ray powder diffraction (XRD)
Thermogravimetric analysis (TG/DTA) 62
Nitrogen adsorption 63
Ultraviolet-visible spectroscopy 64
Raman spectroscopy 66

4. RESULTS AND DISCUSSIONS 67
4.1. Insertion compounds 67
4.1.1. Iodine insertion compounds
4.1.2. Insertion experiments with selenium 78
4.1.3. compounds of mercury(II) halides 88
4.1.4. Gold(III) chloride insertion compounds 98
4.2. Characterization of zeodyes 113
Formation mechanism of 124
Structure of zeodyes 125

5. GENERAL CONCLUSIONS 129

References 133
Table of acronyms 143
Appendices 145
A1. Silicalite-1 as-synthesized 145
A2. calcined 149
IV
A3. HgBr–Silicalite-1 153 2
A4. Au Cl 159 2 6
A5. ITQ-4 as-synthesized 163
A6. calcined 165
A7. I– ITQ-4 168 2
A8. SSZ-24 as-synthesized 170
A9. calcined 171
A10. I–SSZ-24 172 2
A11. Se–SSZ-24 173
A12. HgBr–SSZ-24 175 2
A13. Au Cl 176 2 6
A14. CIT-5 as-synthesized 178
A15. calcined 179
A16. I–CIT-5 180 2
A17. Se–CIT-5 182
A18. HgBr–CIT-5 184 2
A19. Au Cl 186 2 6
A20. UTD-1 as-synthesized 187
A21. calcined/monoclinic 190
A22. UTD-1 calcined/orthorhombic 191
A23. I–UTD-1 192 2
A24. Se–UTD-1 193
A25. HgBr–UTD-1 194 2
A26. Au Cl 196 2 6
A27. HgBr 198 2
A28. AuCl 199 3
A29. AuCl 201
A30. HAuCl 202 4
List of publications 205
Curriculum Vitae 207
V
VI
Abstract


In the first part of this work, insertion compounds of inorganic substances of porosils are
described. Porosils possess pure silica microporous crystalline frameworks; a special class of
porosils are zeosils, which possess channel-type voids. After previous work in our group on
small and medium pore zeosils, the focus here is on large and extra-large pore zeosils, having
channels which are circumscribed by 12 or 14 [SiO ] tetrahedra, respectively. The chosen 4
zeosils are ITQ-4 (IFR), SSZ-24 (AFI), CIT-5 (CFI) and UTD-1(OH). Different inorganic
species, as iodine, selenium, mercury(II) halides and gold(III) chloride were used as guest
components. On the basis of the different pore characteristics of the crystalline host materials,
different stabilities of the insertion compounds were observed, which are related to the strengths
of host-guest interactions. More important, it was also possible to observe different degrees of
guest-guest interactions. Extra-large pore zeosils as UTD-1 also allowed for the insertion of
gold(III) chloride, which cannot be introduced into medium and large pore zeosils.
The second part of the work deals with the synthesis of novel porous materials with a
hierarchical pore structure, the so-called zeodyes. They were prepared using the “clear solution”
and an azo-dye as surfactant. The clear solution is a nanoslab suspension, containing slab
particles with dimensions of 1.3 x 4.0 x 4.0 nm, which possess the crystalline structure of
Silicalite-1. The synthesis conditions were optimized in order to obtain stable and ordered
structures. The newly synthesized materials have layered structures. They were investigated
with powder X-ray diffraction and UV-vis spectroscopy. Upon template removal, materials with
hierarchical pore structures (combined micro- and mesoporosity) were obtained, as shown by