Kinetic and mechanistic studies on the liquid-phase hydrogenation of nitriles and dinitriles over cobalt-based catalysts [Elektronische Ressource] / Peter Schärringer

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• Publié par: technische_universitat_munchen
• Publié le: 01 janvier 2007
• Nombre de lectures: 14
• Langue: English
• Poids de l'ouvrage: 2 Mo

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Technische Universität München
Lehrstuhl für Technische Chemie II




Kinetic and mechanistic studies on the liquid-phase
hydrogenation of nitriles and dinitriles over cobalt-based catalysts



Peter Schärringer





Vollständiger Abdruck der von der Fakultät für Chemie der Technischen
Universität München zur Erlangung des akademischen Grades eines
Doktors der Naturwissenschaften (Dr. rer. nat.)
genehmigten Dissertation.



Vorsitzender: Univ.-Prof. Dr. Bernhard Rieger
Prüfer der Dissertation:
1. Univ.-Prof. Dr. Johannes A. Lercher
2. Univ.-Prof. Dr. Klaus Köhler





Die Dissertation wurde am 15.02.07 bei der Technischen Universität München eingereicht
und durch die Fakultät für Chemie am 13.03.07 angenommen.
Acknowledgements
A bit more than three years ago my gut feeling told me to start a PhD in Johannes’
(Prof. Dr. J. A. Lercher) group. Now that this story comes to an end I can surely say that it
was the right choice thanks to the help and support of many nice and interesting people.
First of all, I want to thank you Johannes for giving me the opportunity to work on a
very interesting and versatile topic, for helpful discussions on scientific and private issues, for
the chance to visit international and national conferences, workshops and research institutes,
which I sincerely did not take for granted.
Special thanks go to PD Thomas Müller, who guided me through the thesis on a daily
basis. Thank you Thomas for your time and patience for discussions even if being busy, for
teaching me how to tackle complex data in a structured way and for the very nice working
atmosphere.
I would like to express my gratitude to PD Andy Jentys who helped me with the calcu-
lation and interpretation of INS data and chose good slopes in Obertauern.
Thank you, Dr. Dirk Bühring, Andreas Gallas and Dr. Olaf Wachsen for fruitful dis-
cussions and a very cooperative and pleasant atmosphere in our meetings.
During the last 3 years life would not have been the same fun without the members of
the TC II group. I very much appreciated getting to know nice people from all over the world,
who created an exciting, exotic and always very cooperative working atmosphere, which
made time running like hell. I would like to thank the technical team consisting of Xaver (the
most demanded person in the institute), Andreas M. and Martin for their indispensable work
and not to forget the TC II guys from the workshop. Thank you, Heike, Helen and Heidi
Hermann for caring about administration. Thank you, Philipp, Hendrik, Virginia, Elvira, Ben-
jamin, Wolfgang, Andreas, Felix, Manuel, Maria, Carsten, Christoph, Aon, Lay Hwa, Oriol,
Manuela, Herui, Tobias, Christoph, Richard, Jürgen, Frederik, Stephan R., Deachao, Prado,
Matteo, Florian, Sandra, Chintan, Krishna, Rhino, Olga, Roberta, Yongzhong, Ghosh,
Praveen, Iker, Christian, Su, Alex, Florencia, Renate, Su, Stefan G., Wolfram, Xuebing,
Adam, Ayumu, Ana and Augustiner. Thank you, Wolfgang, Franzi, Cen and Yuying for do-
ing eminent experimental work during your diploma and semester theses.
Very special thanks go to my parents (Annemarie and Franz) and my sister (Patricia),
without the help of which I would never have come to that point. And finally my biggest
thanks go to Johanna simply for being there and for your optimistic way of interpreting
things. When driving the long way home it was always good to know that you would soon
make me smile.
Table of contents
Table of contents
Chapter 1 General Introduction......................................................................................... 1
1.1. IMPORTANCE AND INDUSTRIAL-SCALE PREPARATION OF ALIPHATIC AMINES ................. 2
1.2. CATALYSTS AND PROCESSES USED FOR THE HYDROGENATION OF NITRILES................... 3
1.3. KINETIC AND MECHANISTIC ASPECTS OF THE HYDROGENATION OF NITRILES ................. 4
1.4. SCOPE AND OUTLINE OF THE THESIS............................................................................... 8
Chapter 2 Experimental.................................................................................................... 11
2.1. STIRRED TANK REACTOR.............................................................................................. 12
2.2. CONTINUOUS TRICKLE BED REACTOR........................................................................... 13
Chapter 3 Co-adsorption of CD CN and hydrogen on a Raney-Co 3
catalyst studies by inelastic neutron scattering............................................... 15
3.1. INTRODUCTION ............................................................................................................ 16
3.2. EXPERIMENTAL............................................................................................................ 17
3.2.1. Materials.............................................................................................................. 17
3.2.2. Catalyst characterization ..................................................................................... 17
3.2.2.1. H -Chemisorption and N -physisorption ..................................................... 17 2 2
3.2.2.2. Thermogravimetry........................................................................................ 17
3.2.3. Hydrogenation experiment .................................................................................. 18
3.2.4. Inelastic Neutron Scattering experiments and sample preparation ..................... 18
3.2.5. Computational methods....................................................................................... 19
3.3. RESULTS ...................................................................................................................... 20
3.3.1. Adsorption of H and CD CN on Raney-Co ....................................................... 20 2 3
3.3.2. H/D exchange and selectivity in the hydrogenation of CD CN.......................... 22 3
3.3.3. Results of INS measurements.............................................................................. 24
3.3.3.1. Hydrogen adsorption on Raney-Co studied by INS..................................... 24
3.3.3.2. Co-adsorption of CD CN and hydrogen on Raney-Co................................ 26 3
3.4. DISCUSSION ................................................................................................................. 31
3.4.1. Role of hydrogen sorption strength ..................................................................... 31
3.4.2. Intermediate species in the co-adsorption of CD CN and hydrogen on 3
Raney-Co............................................................................................................. 32
3.5. CONCLUSIONS.............................................................................................................. 36


I Table of contents
Chapter 4 Investigations into the mechanism of the liquid-phase
hydrogenation of nitriles over Raney-Co catalysts......................................... 39
4.1. INTRODUCTION ............................................................................................................ 40
4.2. EXPERIMENTAL............................................................................................................ 42
4.2.1. Materials.............................................................................................................. 42
4.2.2. Catalysis .............................................................................................................. 42
4.3. RESULTS ...................................................................................................................... 44
4.3.1. Hydrogenation of C –C≡N and CD CN.............................................................. 44 1 3
4.3.2. Hydrogenation of C –C≡N.................................................................................. 49 3
4.3.3. Co-hydrogenation of C –C≡N and C –C≡N ....................................................... 50 1 3
4.3.4. Hydrogenation of C –C≡N in the presence of C –NH ....................................... 53 1 4 2
4.3.5. Hydrogenation of C –C≡N in the presence of C –NH ....................................... 55 3 2 2
4.4. DISCUSSION ................................................................................................................. 57
4.4.1. H/D exchange and kinetic isotope effect in the hydrogenation of
CD CN................................................................................................................. 57 3
4.4.2. Role of the strength of adsorption ....................................................................... 58
4.4.3. Mechanistic aspects of the formation of dialkylimines....................................... 60
4.4.4. Mechanistic aspects of dialkylimine hydrogenation ........................................... 62
4.5. CONCLUSIONS.............................................................................................................. 64
Chapter 5 Tailoring Raney-catalysts for the seclective hydrogenation
of butyronitrile to n-butylamine ...................................