Son Nguyen promoted December 4th, 2014This thesis aims to develop an efficient catalyst to upgrade bio-oil into high quality fuel via de-oxygenation and hydro-deoxygenation. The second part is dedicated to study the nature of the active specie in the newly-developed catalyst and to gain more insight into the catalytic conversion of lignin via a model compound study.

THỊ MINH CHÂU HOÀNG Promoted July 18th, 2014The whole process of humin gasification was studied. Humin is a potential
carbonaceous material for producing sustainable hydrogen. The thesis covers fundamental
investigation on chemical structure of humin byproduct from de-hydration of D-glucose for
making levulinic acid (a bio chemical building block) as well as the entire gasification of
humin (devolatilisation, gasification, steam reforming of tar). The findings in this thesis can
also contribute to gasification of a wider bio-derived feedstock range (e.g., lignocellulose,
bio-oils).

Masoud Zabeti promoted June 4th, 2014Currently, there are tremendous interests in developing catalysts to
make this conversion efficient and to improve the properties of bio-oil to suit
applications, for example as feedstock in a conventional oil refinery. This thesis
focuses on the development of such a catalyst for ,more specifically, in-situ
catalytic deoxygenation.

Arturo Susarrey Arce promoted April 11, 2014Arturo Susarrey Arce defended his PhD thesis entitled: “Switching activation barriers: New insights in E-field driven processes at the interface”.

Shilpa Agarwal promoted April 3th, 2014Dr. Shilpa Agarwal demonstrated that the physical form and size of the catalyst CeO2 play a significant part. For example, she showed that cube-shaped nanoparticles of the material possess the highest activity.

Dennis de Vlieger promoted Februari 8th, 2013Biomass is believed to be a promising renewable energy source for the future.
Conversion of biomass waste to liquid fuels or hydrogen is projected to provide, partly, the
required energy demand. The anticipated intensification of biomass conversion processes will
result in an increase in biomass derived aqueous waste streams

Sergio Pacheco Benito promoted October 26th, 2011This thesis describes the preparation of CNF layers on flat and porous substrates and their application as catalyst supports for chemical and electrochemical gas‐liquid‐solid (G‐L‐S)
catalytic reactions. The last part describes the water wettability properties of CNF layers that can have application in microfluidic devices.

Digvijay Bhagwan Thakur promoted October 29th, 2010Vijay Thakur describes in his thesis various aspects of the development of carbon nanofiber supported catalyst layers on structured internals of microreactors made from silicon technology based materials (e.g. fused silica and/or silicon). These microreactors are intended to be used for heterogeneously catalyzed liquid phase reactions, in this case for aqueous phase removal of nitrite and bromate to evaluate the performance of such systems and demonstrate their benefit over conventional catalyst support material.

Cassia Boyadjian promoted September 24th, 2010Oxidative Cracking of n‐Hexane a catalytic pathway to olefins

Cassia Boyadjian presents her thesis study carried in the group of Catalytic processes & Materials under the supervision of Prof. L. Leffers and Dr. K. Seshan, on September 24th, 2010. Her thesis outlines the successful development of a catalyst based on studies involving model molecules representing refinery feedstock and relationships drawn from kinetic, catalytic and spectroscopic correlations for the reaction.

Jitendra Kumar Chinthaginjala promoted June 18th, 2010Jitendra Kumar Chinthaginjala of the University of Twente has developed a catalyst that can efficiently remove nitrite and nitrate from drinking water. These two toxic substances are increasingly found in drinking water in areas with intensive agriculture. The catalyst converts nitrite and nitrate, in combination with hydrogen, into harmless nitrogen. Chinthaginjala received his doctorate from the Faculty of Science and Technology on June 18.

Davide Crapanzano promoted May 28th, 2010Davide Crapanzano of the University of Twente and the IMPACT research institute has demonstrated the conditions under which a new catalytic membrane can be used for the cheaper, faster and more energy-efficient production of raw materials for the plastics industry. In this way propane can be more quickly converted into propene, and then for example into polypropene, which is used as a raw material for garden furniture, car components and other products. Crapanzano obtained his PhD on 28 May from the Faculty of Science and Technology.

Berta Matas Güell promoted October 9th, 2009The research described in this thesis focuses on the production of hydrogen from biomass-based feedstocks as renewable sources; particularly, via the catalytic steam reforming of pyrolysis oil. Pyrolysis oil, which is produced by the thermal cracking of wood, consists of a large number and variety of oxygenated components. Due to the complexity of this feedstock, it is too difficult to draw relations between structure, properties and reaction mechanism.

Patrick Graf promoted January 23rd, 2009The research discussed in this thesis and the parallel work by Tymen Tiemersma evaluated the possibilities of combining the oxidative coupling and reforming of methane in one multifunctional reactor. Several aspects related to catalyst and reactor development were investigated and are described in the two PhD theses.

Cristiano Trionfetti promoted May 29th, 2008Due to a cold plasma, hydrocarbon activation via hemolytic C-H and C-C bond rupture (forming radicals) occurred exclusively in the gas phase at near ambient temperatures (<50°C). In contrast to the results obtained at higher temperatures (=>550°C), in all the experiments performed in a plasma micro-reactor, mainly products that require the formation of C-C bonds were observed. Indeed, C-C bond formation is an exothermic process and therefore favored at lower temperatures.

Dejan Radivojevic promoted May 23th, 2008The work described in this thesis focuses on development and application of a transient response technique for studies of adsorption and catalytic reactions over heterogeneous catalysts in liquid phase with Electro-Spray Ionization (ESI-MS) and Membrane Inlet Mass Spectrometry (MIMS) as detectors. Two test reactions, i.e. reduction of nitrite over Pt/SiO2 and oxidation of glucose over Pt/CNF/Ni catalysts, were used to demonstrate that it is possible to monitor reactants, intermediates and products during reaction in (semi)quantitative manner.

Khalid Azzam promoted May 9th, 2008The suitability of polymer electrolyte fuel (PEM) cells for stationary and vehicular applications initiated research in all areas of fuel processor (i.e. reformer, water-gas-shift, preferential oxidation of CO (PROX)) catalysts for hydrogen generation. Water gas shift (WGS) reaction is an essential part of these processors because of its role in CO purification, which poisons the Pt electrodes of PEM, and its role in generating additional hydrogen.

Sune Ebbesen promoted March 8th, 2007The work described in this thesis demonstrates the application of ATR-IR infrared
spectroscopy to study adsorption and catalytic reactions on metal surfaces during
heterogeneous catalytic reactions in aqueous phase. By coating an Internal
Reflection Element (IRE) with a stable, thin (in the order of a few microns) catalyst
layer, adsorption and reaction at the solid-aqueous interface was studied
successfully.

Jiang Xu promoted June 9th, 2005This thesis focuses on investigation of the fundamental knowledge on a new method for selective oxidation of propane with O2 at low temperature (< 100°C). The relation between propane catalytic selective oxidation and physicochemical properties of cation exchanged Y zeolite has been studied. An attempt has been made to determine how propane oxidation activity and selectivity are influenced by charge-compensating cations, acidity and geometry of zeolites.

Jianjun Zhu promoted March 24th, 2005The work presented in this thesis provides both
fundamental scientific knowledge as well as a new technical dual-bed concept for synthesis
gas production via catalytic partial oxidation of methane over defective ZrO2-based oxides.

Nabeel Jarah promoted October 28th, 2004This thesis provides information about the preparation of micro-structured materials based on carbon nano-fibers (CNFs)