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Sulfur and Nitrogen Sensitivity of Supported Pt-Hydrogenation Catalysts

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Sulfur and Nitrogen Sensitivity of Supported Pt-Hydrogenation Catalysts Technische Universität München Lehrstuhl für Technische Chemie II Sulfur and Nitrogen Sensitivity of Supported Pt-Hydrogenation Catalysts Maria Florencia Williams Vollständiger Abdruck der von der Fakultät für Chemie der Technischen Universität München zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigten Dissertation. Vorsitzender: Univ.-Prof. Dr. Klaus Köhler Prüfer der Dissertation: 1. Univ.-Prof. Dr. Johannes A. Lercher 2. Univ.-Prof. Dr. Kai-Olaf Hinrichsen Die Dissertation wurde am 02.06.05 bei der Technischen Universität München eingereicht und durch die Fakultät für Chemie am 15.06.05 angenommen. Acknowledgements First of all I would like to thank Johannes Lercher for giving me the opportunity to work in his group. Thank you for your guidance and support during my Ph.D. I greatly enjoyed the scientific freedom you granted me, still watching carefully the steps leading to the final success. I was always enlightened to hear your point of view, be it on the deeper insights of chemistry, be it on the more technical side of the work, be it on matters not related to any of the above. I am grateful for the financial support provided by Shell Chemicals. I am very much indebt with Rob van Veen and Wim Stork who cooperated in this project. Thanks Rob for your fruitful discussions and for your always very good mood. From the Shell team I would also like to thank Arend-Jar for his advice concerning the hydrogenation set-up and also for introducing me to the synthesis of the catalysts used in this work. Thanks Andy for the help and discussion with the XAFS data, Marianne for introducing me in the use of the electron-microscope and Jeroen for the interesting NMR discussions Thanks Xaver, Martin and Andreas for your help with measurements and troubleshooting Thanks to all the TC2 people, it was really nice working with all of you. Thanks for being so cool and friendly. I am very glad that I had the chance to meet you, this was a wonderful experience and I will never forget you! Last but not least, I would like to thank my family and my friends outside TC2 Chapter 1 General introduction 1 Motivation....................................................................................................................2 1.1 Economic significance of diesel fuel...................................................................2 1.2 Emissions from diesel engines.............................................................................2 1.3 Environmental legislation on diesel fuel..............................................................4 2 Catalytic hydrotreating.................................................................................................5 2.1 Saturation of aromatic hydrocarbons ...................................................................6 2.2 Hydrodesulfurization (HDS)................................................................................7 2.3 Hydrodenitrogenation (HDN)..............................................................................8 2.4 Hydrotreating in refining ...................................................................................10 2.5 Deep catalytic hydrotreating..............................................................................11 3 Mechanistic aspects in the catalytic hydrogenation of aromatics..............................14 3.1 Sulfur tolerance of noble metals. .......................................................................14 4 Scope of the thesis......................................................................................................15 5 References..................................................................................................................17 Chapter 2 Characterization of ASA-supported platinum catalysts by 27Al (3Q) MAS NMR, 1H MAS NMR, FTIR, TPD, TEM, and EXAFS 1 Introduction................................................................................................................20 2 Experimental..............................................................................................................22 2.1 Preparation and chemical composition of supported Pt-catalysts......................22 2.2 Specific surface area and porosity.....................................................................22 2.3 Nuclear magnetic resonance spectroscopy........................................................22 2.4 Infrared spectroscopy.........................................................................................23 2.5 Temperature programmed desorption................................................................24 2.6 Transmission electron microscopy.....................................................................24 2.7 H2 Chemisorption...............................................................................................24 2.8 Extended X-ray absorption fine structure ..........................................................25 3 Results........................................................................................................................26 3.1 Chemical composition, textural properties and bulk structure of the catalysts .26 I 3.2 Surface structure of the Pt-catalysts...................................................................30 3.3 Characterization of platinum nanoclusters.........................................................37 4 Discussion..................................................................................................................42 4.1 The formation of brønsted acid sites in the ASA-supported Pt-catalysts ..........43 4.2 Characterization of platinum phase in the ASA-supported Pt-catalysts............44 5 Conclusions ................................................................................................................46 6 References..................................................................................................................48 Chapter 3 Metal-support interaction: influence of the support on the catalytic activity of platinum for deep hydrotreating 1 Introduction................................................................................................................52 2 Experimental..............................................................................................................55 2.1 Catalytic testing..................................................................................................55 3 Results and discussion...............................................................................................58 3.1 Characterization of the supported Pt-catalysts...................................................58 3.2 Hydrogenation of tetralin...................................................................................59 3.3 Hydrogenolysis of neopentane...........................................................................63 3.4 Electronic structure of platinum by XANES .....................................................67 4 Conclusions ................................................................................................................69 5 References..................................................................................................................70 Chapter 4 Mechanistic aspects of tetralin hydrogenation in the presence of poisons 1 Introduction................................................................................................................73 2 Experimental..............................................................................................................74 2.1 Catalytic measurement .......................................................................................74 2.2 Characterization of spent catalyst samples ........................................................75 3 Results........................................................................................................................77 3.1 Characterization of supported Pt-catalysts.........................................................77 3.2 Hydrogenation of tetralin in the presence of quinoline .....................................78 II 3.3 Hydrogenation of tetralin in the presence of DBT.............................................81 3.4 Analysis of the spent catalyst samples...............................................................86 4 Discussion..................................................................................................................91 4.1 Hydrogenation of tetralin in the presence of quinoline .....................................91 4.2 Hydrogenation of tetralin in the presence of DBT.............................................92 4.3 Proposed hydrogenation model..........................................................................93 5 Conclusions ................................................................................................................94 6 References..................................................................................................................95 Chapter 5 Summary Summary............................................................................................................................98 Zusammenfassung............................................................................................................101 III Chapter 1 Introduction This chapter introduces to the importance of Diesel fuel, presents catalytic routes to high quality Diesel and highlights the motivation for the research conducted. Finally, the milestones
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