Title Promoter Affiliations Abstract "Electrosynthesis for the sustainable production of ethylene oxide." "Tom Breugelmans" "Applied Electrochemistry & Catalysis (ELCAT)" "BASF is wereldwijd de grootste multinational in de chemische sector en in België gevestigd in de Antwerpse haven. De vestiging omvat onder andere de grootste ethyleenoxide (EO) productieafdeling in Europa. Het huidige EO-productieproces verloopt via katalytische oxidatie. Hierbij verbrandt echter een substantieel deel van de voeding tot CO2. Gedreven door de ontwikkelingen op klimatologisch vlak en de te verwachten heffingen op broeikasgassen staan milieubelastende processen onder druk en wordt de omschakeling naar groenere processen gestimuleerd. Zo werd onder andere een actieplan van de EU in het leven geroepen om de opwarming van de aarde af te remmen en onder de 2°C grenswaarde te houden. Het plan stelt dat 40% afslanking van de broeikasgasuitstoot, 27% verhoging van de energie-efficiëntie en 27% verhoging van de groene stroom gerealiseerd moeten worden voor 2030. BASF volgt deze filosofie en werkt toe naar een CO2 vrije groei tegen 2030. Het bedrijf wil zich dan ook inzetten voor de ontwikkeling van een groen EO productieproces en is daarom samen met de ART onderzoeksgroep het engagement aangegaan voor de uitwerking van een Baekeland project. Een elektrosynthese methode biedt de mogelijk om een CO2 vrije productie van EO te realiseren. Elektrochemische processen verlopen doorgaans bij veel lagere temperaturen (< 100°C), waardoor verbrandingsreacties, en bijgevolg de CO2 uitstoot, volledig vermeden kan worden. De laatste decennia heeft de elektrochemische technologie grote stappen voorwaarts gemaakt onder impuls van nieuwe technieken en inzichten op vlak van materiaaltechnologie, oppervlakte-engineering, membraan-technologie en gasdiffusie-elektroden (GDE)." "Construction of a prototype electrosynthesis reactor" "Tom Breugelmans" "Applied Electrochemistry & Catalysis (ELCAT)" "The production of organic chemicals by means of electrosynthesis can dramatically increase reaction efficiency. The approach of this project is to construct a prototype reactor setup to facilitate the transition from classical chemical towards electrochemical pathways. The modular reactor setup will be an ideal platform to develop electrosynthesis reactions and to transfer knowledge towards future follow-up projects." "New redox mediators and improved electrocatalytic materials for the functionalization of carbon-hydrogen bonds by electrosynthesis." "Tom Breugelmans" "Organic synthesis (ORSY), Applied Electrochemistry & Catalysis (ELCAT)" "Functionalization of inert carbon-hydrogen (C-H) bonds is an important reaction in the chemical industry. The introduction of functional groups (e.g. oxygen, nitrogen, sulfur, … atom) in otherwise inert molecules is necessary to construct more complex molecules for the bulk and fine chemicals industry. However, an organic molecule contains multiple C-H bonds (the most common bond in organic molecules) and the selective functionalization of a specific C-H bond with chemical reactants is therefore very difficult to achieve. New chemoselective C-H functionalization methods for late stage functionalization with the production of low amounts of (harmful) waste are therefore important to make organic synthesis more efficient and sustainable. Electrosynthesis is a promising alternative, although currently suffering from low chemoselectivity. By adding a homogeneous catalyst (redox mediator) this lingering problem can be overcome, but an electrochemically activation step of the redox mediator is required. In the current state-of-the-art this is performed with inert electrode materials (e.g. glassy carbon), resulting in low yield and energy intensive processes with excessive required amounts of redox mediator. Hence, there is a strong need for improved electrocatalytic materials in combination with more active redox mediators. In general this research projects aims to develop new electrocatalytic materials for the charge transfer to redox mediators for C-H bond cleavage in organic substrates. To achieve this goal we will use a step-wise electrocatalytic approach to obtain an optimal catalytic performance for the charge transfer to redox mediators. In a first step, bulk electrode materials will undergo a preliminary screening to identify possible materials that possess high electrocatalytic activities. In a second step, the activity of the electrode surface is further improved by (i) moving towards nanoparticles dispersed on a support and (ii) by introducing an alloy with a second or third metal. The redox mediator represents one of the key-elements in successfully implementing C-H bond functionalization. Therefore, we will examine redox mediators in combination with the electrocatalysts. As a case-study the electrochemical C-H oxygenation making use of quinuclidine mediator will be selected as model reaction.The above mentioned research questions will require an intertwined approach combining electrocatalysis (expertise of the ART research group) with state of the art organic synthesis (expertise of the ORSY research group)." "Towards a targeted optimization of electrocatalysts by combining electrosynthesis with in-situ electron paramagnetic resonance." "Tom Breugelmans" "Biophysics and Biomedical Physics, Applied Electrochemistry & Catalysis (ELCAT)" "In recent years, there has been a growing search for clean, environmental friendly methodologies for organic synthesis. Organic electrochemistry offers an interesting alternative to tackle the issues for organic transformations. Electrochemical synthesis mostly needs fewer steps and produces less waste with the electron as a cheap, clean and energetically efficient reagent. However, the applicability of electrosynthesis depends on the selection of the electrocatalyst as a way to decrease the energy demand of the reactions. In the current state of the art, these catalysts are still subject to further improvements. In our opinion, developing sufficient theoretical knowledge about the reaction mechanism on the electrode surface for very specific electrochemical reactions is essential to tune these catalysts. Therefore, we will use a combination of in situ electrochemistry and electron paramagnetic resonance (EPR) to unravel the underlying mechanism. The final goal is to develop an approach that provides an in-depth understanding of reaction mechanisms and that links the electrocatalytic and electrosynthetic features to the morphology and stability of the electrode material. To reach this goal, a combination of electrochemical techniques, in-line analytical methods and different EPR techniques will be used. New flow cells will be constructed in addition to existing static cells to unravel the electrode kinetics and to assess the activity of different electrocatalyst materials." "Targeted optimization of electrocatalysts by combining electrosynthesis with in situ electromagnetic resonance" "Annick Hubin" "Materials and Chemistry" "Targeted optimization of electrocatalysts by combining electrosynthesis with in situ electromagnetic resonance" "Optimalisation of the microbial electrosynthesis by Clostridium ljungdahlii" "Korneel Rabaey" "Department of Biochemical and microbial technology" "Microbial electrosynthesis is the process in which bacteria use electrical energy to convert CO2 into organic compounds. A promising bacterium for this process is Clostridium ljungdahlii. Electrosynthesis by this bacterium will be optimized by developing a strain with an increased biofilm production and an enhanced electron transfer, as well as by improving the operational conditions for reactors." "Continuous Flow Electrosynthesis of Macromolecules in a Sonicated Microreactor Setup" "Simon Kuhn" "Sustainable Chemistry for Metals and Molecules, Process Engineering for Sustainable Systems (ProcESS)" "Atom transfer radical polymerization (ATRP) is a versatile technique for exerting precise control over polymer molecular weights, molecular weight distributions, and complex architectures. Electrochemically mediated ATRP (eATRP), as a young member in the ATRP family, is particularly interesting for its various advantages such as in situ generation of active catalyst, real-time control of reaction rate, and enhanced tolerance to oxygen. A simplified version of eATRP (seATRP) that reduces the complexity of the reaction setup has also been developed by the introduction of a sacrificial aluminum anode. However, due to the electrochemical nature of seATRP, there are still some inherent limitations, e.g., difficulty in scaling up and the need for supporting electrolyte. Flow chemistry and continuous flow microreactors present solutions to these challenges. The tiny spacing between electrodes offers the possibility of a self-supported reaction, and the very large reactor surface-to-volume ratio could also improve the mass transfer and thus increase the reaction rate. Furthermore, the simple scale-up strategy could also address the scalability challenge. Despite these advantages, mass transfer in a continuous flow microreactor generally relies on diffusion, and therefore, the mixing efficiency is limited. One promising tool to solve these problems is ultrasound. When applied at appropriate conditions, ultrasound is able to induce an acoustic streaming inside the reactor, thus enhancing the mixing efficiency. Therefore, the main aim of this thesis is to investigate the application of a novel sonicated microreactor in continuous flow electrosynthesis of macromolecules, with a focus on the seATRP reaction." "Microbial electrosynthesis via intermediates" "Department of Biotechnology, Department of Biochemical and microbial technology" "This Ph.D. proposes a novel strategy to produce biochemicals out of CO2 in a bioelectrochemical system. The electricity-driven microbial conversion of CO2 into multi-carbon compounds is described as microbial electrosynthesis. This proposal describes a different approach to MES, based on the fermentation of CO2 and (bio)electrochemically produced intermediates. These intermediates have the potential to tackle the limitations associated with MES." "Inorganic Electrosynthesis via the Oxygen Reduction Reaction" "Jan Fransaer" "Surface and Interface Engineered Materials (SIEM)" "The process employs a gas diffusion cathode that (in most cases) allows the transport of oxygen into the electrochemical cell. At this electrode, a number of complex processes occur. The oxygen, the electrons and the electrolyte coincide to form a triple interphase. The (negative) potential applied will reduce oxygen to peroxide-related species that can in turn oxidize metal ions in the solution. Simultaneously in all the oxygen reduction reactions, hydroxide ions are formed. It is clear that one of the main topics of this work will relate to understanding the Oxygen Reduction Reactions (ORR) in uncatalyzed carbon electrodes. Furthermore, the changing chemical composition of the media and the large shift in pH-potential through the process leads to very interesting case-studies for the inorganic chemistry of our selected metals.The work will be carried out with two main objectives:To elucidate the fundamental processes ocurring in GDEx in terms of electrochemical reactions, charge transfer, kinetics, thermodynamics and particle formation and growth. Electrochemical techniques (CA, CV, EIS, etc.), Spectrophotometry, Electron Microscopy (SEM and TEM), X-Ray Diffraction, FTIR, ICP-MS, SP-ICP-MS, among others are the techniques that will be employed in this study.To explore a large range of possible applications for this technology and tackle scientifically, and industrially, interesting materials." "Degradation Testing of Magnesium and its Alloys aiming at Biodegradable Implant Applications" "Omer Van der Biest" "Surface and Interface Engineered Materials" "Magnesium and its alloys are increasingly interesting materials for biodegradable implant applications. The advantage of these implants is that they gradually degrade in the human body after fulfilling the purpose of their implantation. For instance, biodegradable implants can be used in orthopaedic applications such as fracture stabilisation, eliminating the need of a second operation for non-degradable implant, e.g. titanium removal. One challenge of biodegradable Mg implants is that the properties required by the implants are application-specific. This means that the implant must be selected depending on both implantation site and patient characteristics in order to obtain the correct implant performance during the healing process.Therefore, in this thesis, swift and slow degrading Mg alloys are studied, by adding silver (Ag) and gadolinium (Gd) as alloying elements, respectively. On the one hand, corrosion can be accelerated by adding Ag increasing the antibacterial properties of the Mg alloy. On the other hand, Mg-Gd binary alloys show a slow degradation due to the reduction of the influence of impurities such as Fe, Ni or Cu. Pure Mg and Mg-4Y-3RE are also included as references to other studies. The reason to choose Mg-4Y-3RE is because it is similar to the alloys currently applied as biodegradable implants. Thus, the degradation behaviour of these Mg based materials are studied by applying electrochemical and immersion testing techniques. In order to understand the Mg degradation, many factors have to be considered regarding testing conditions and material.Firstly, the testing conditions have a large influence on the Mg alloy degradation behaviour. These conditions are mainly defined by electrolyte, buffering, atmosphere, electrolyte volume to sample surface (V/S) ratio and sample positioning. With the aim to investigate some of these factors different testing conditions have been applied in immersion tests in vitro of the Mg based materials introduced above. The media applied in vitro are: phosphate buffered saline (PBS), Hank’s balanced salt solution (HBSS) and Dulbecco’s modified eagle medium (DMEM). When DMEM is applied also 5 vol.% of CO2 is added to the atmosphere to increase the buffering capacity. Large differences in degradation rate are found between Mg-Gd and Mg-Ag in PBS and HBSS while in DMEM the difference in degradation rate is reduced. Basically the chlorine content in the medium and the degradation layer formation process have a crucial influence on the degradation behaviour.Secondly, the degradation behaviour of the material also depends on the different alloying additions and processing routes which induce considerable alterations of the microstructure and impurity content. Therefore, the degradation behaviour of pure Mg, Mg-10Gd and Mg-2Ag, produced in disc and pin shape, are compared by in vitro and in vivo experiments, respectively. This analysis reveals the large influence of the impurity content of Fe and Ni as well as the grain size on the degradation performance in vivo, whereas the role of alloying additions such as Gd and Ag are found less important. In this study, the degradation rate and the surface layers determined in DMEM are found more comparable to those determined in vivo. This indicates that DMEM mimics more closely in vivo conditions. However, to achieve this mimicking when DMEM is applied, the need of sterilization measures has been identified. Otherwise, medium contamination will accelerate the Mg degradation behaviour by acidifying the electrolyte and dissolving Ca and P rich corrosion products present at the degradation layer.Electrochemical methods, such as potentiodynamic polarization (PDP) experiments, give a quick comparison between the degradation profiles of different Mg alloys. This technique is commonly used as the first test for degradation characterization. However, the surface layer formation during polarization under non-dynamic conditions is considered to play a major role in the results. The use of the rotating disc electrode (RDE) can induce a dynamic flow at the Mg working electrode, increasing the transport of the dissolved Mg2+ ions away from the surface and reducing the surface layer formation. Parameters such as rotation speed and scan rate have been analysed finding that values higher than 1500 rpm for the rotation and 5 mV/s for the scan rate allow for more reproducible measurements without degradation layer deposition. Hence, PDP measurements with the RDE can show repeatedly characteristic curves of the material-electrolyte system and give what is considered a better estimation of the initial degradation rate.Surface treatments are widely studied in order to tailor the surface properties and the degradation behaviour of Mg implants. Some coatings could allow the addition of a drug to the implant which could help during the first inflammatory reaction or during the healing process. In this thesis, the first steps towards a new biodegradable drug delivery system are shown. This system consists of metal organic frameworks (MOFs). MOFs are promising materials as drug nano-carriers for their nanoporous structure and, in literature, they are also considered “bio-friendly”. Mg can be used as the metal in the MOF structure, which is called Mg-MOF. Currently, Mg-MOF is produced hydrothermally, and in this thesis, Mg-MOF layers are electro-synthesised on a Mg substrate, which would add the drug delivery capacity."