The industrial revolution caused the release of carbon dioxide (CO2) into the atmosphere leading to a climate crisis. The impact of more CO2 in the atmosphere has been experienced by everybody. The summers are longer and hotter, while the winters are colder and shorter. The ocean water has become more acidic threatening the ocean life. There is an immediate need to reduce CO2 and switch to alternate energy for human survival. Electrochemical reduction of CO2 (ERC) is a promising technology capable of converting excess CO2 into valueded products. The process of recycling CO2 can address the problem of excess CO2 and is a sustainable solution until our dependence on fossil fuels is reduced. However, currently there are very few catalysts that can convert CO2 into valuable products with a low overpotential. The current research evaluates new catalysts for their ERC potential. [Ni(cyclam)]2+ is a well-known catalyst used to reduce CO2 homogeneously. Therefore, it was used as a standard to optimize the CO2 evaluation protocol. Two new catalysts developed in Dr. Hollis's laboratory, a Pt- pincer and a Fepincer molecule were assessed using this method. Cyclic voltammetry and bulkelectrolysis (BE) experiments were performed under Ar and CO2 environments. The gaseous products from BE were primarily CO and H2 and their quantitative measurement was performed using gas chromatography. Formate determination was performed using UV-Vis spectroscopy. Faradaic yields were calculated for CO, H2, and formate. The overpotentials were calculated for all the processes, and a comparison was made to determine the most efficient process. The turnover numbers (TON) and the turnover frequencies (TOF) of all the catalysts were calculated. Based on all the criteria, the Fepincer complex was determined to be the most promising catalyst for further optimization. Additionally, a Faradaic efficiency calculation spreadsheet was created to improve calculation efficiency. The protocol described here has been successfully applied to assess new catalysts and can prove to be an invaluable tool when numerous catalysts require evaluation.

This dissertation is written in two sections. The first section deals with the development of methods for the estimation of the effective electrolytic surface area of rough and porous silver electrodes in alkaline electrolyte. Data are presented comparing the results of three different methods of surface area estimation. Model pore electrodes were also prepared and oxidized to study the reactions in a pore. Data for constant current oxidations of these electrodes is given. The second section deals with the potentiostatic oxidations of silver in alkaline electrolyte. Data are presented on the total charge acceptance versus applied potential for a potential range that runs from the potential required to first produce silver (I) oxide to that required to evolve oxygen off the surface of the electrode. The shape of this plot indicates the formation of two types of silver (I) oxide. Three oxidation reactions were noted. The first was the formation of silver (I) oxide. The second was the formation of silver (II) oxide. The nature of the third reaction is not yet known; however, some evidence indicates it is the formation of silver (III) oxide.

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Shifting from fossil fuels and moving towards sustainable and environmentally friendly fuels is vital to combat global warming. Hydrogen's high energy content and abundance on earth qualify it as one of the primary clean fuels, especially when produced from renewable resources. However, the way of clean hydrogen production and its environmental effect is still in the research and development stage. Hydrogen production, use as aviation fuel, storage, and transportation pose a technological challenge to overcome. This thesis project studied one of the aspects of hydrogen usage in the aviation sector by finding the optimum hydrogen production pathway in airports to fuel aircraft. Stockholm Skavsta airport was taken as a study case. Through literature review, hydrogen production methods were evaluated. Water electrolysis was found to be the optimum method to produce hydrogen for such application because of its production plant's simplicity and the possibility of having no emissions during the production when renewable energy is used. The optimum sizing and scheduling of hydrogen production and storage in Stockholm Skavsta airport were found for three electrolysis systems (Alkaline, PEM, and solid oxide) and three processes and storage types (compressed gas, cryo-compressed and liquefied). The study assessed three power sources to supply the necessary power for the production and storage ( grid supply, grid +solar system, and pure renewable solar PV +wind). The study considered 27 scenarios covering all the possible combinations of electrolysis systems, storage types, and power sources.   The levelized cost of hydrogen and carbon dioxide emissions was lower for the solar + grid scenarios, while grid powered scenarios gave the highest Levelized cost and carbon emissions. The pure renewable energy scenarios were nonfeasible due to the low renewable resources near the study case location. The optimum levelized cost of hydrogen was found to be between 2.93 - 2.44 Euro/kg, and the annual carbon dioxide emissions were in the range of 34731.1 to 20861.3 tons/year.  The PEM electrolysis showed the highest Levelized cost and moderate emissions, while the Alkaline electrolysis showed the highest carbon emissions and moderate cost. The lowest levelized cost and emissions were for the solid oxide electrolysis system. This thesis project succeeded in finding a pathway for inhouse hydrogen production for airports that might even be of interest being utilized in different sectors

To enable the use of renewable energy throughout the system, the Dutch government aims to rely strongly on hydrogen gas as a green energy carrier. This thesis is dedicated to assessing the feasibility of meeting the future Dutch hydrogen demand with locally produced green hydrogen through offshore wind. The aim was realized by modelling the Dutch hydrogen demand in 2050 based on government plans and comparing this with the amount of green hydrogen the Netherlands can produce through offshore wind. Methods used include extensive literature reviews, energy system modelling, scenario analysis, and calculations. The results show that between 1,28 and 2,04 EJ of wind energy is necessary to meet the regular electricity demand and the electricity demand for hydrogen production through electrolysis. This needs to be compared to an offshore wind energy potential in the Dutch North Sea that ranges between 0,67 and 1,79 EJ. An analysis of the results shows that the offshore wind demand could be met, but it is more likely that the offshore wind energy potential is insufficient to meet the demand. The government envisions five applications for hydrogen, namely to be used as feedstock for the process industry, to generate high temperature heat, as energy storage for renewables (balancing the grid), as a transport fuel, and in the built environment. The results indicate that the demand of these five applications is unlikely to be met completely with offshore wind green hydrogen. However, the large majority of the hydrogen demand is dedicated to be used as a feedstock for the process industry. If this feedstock were to be from another source, meeting the demand of the remaining hydrogen applications with offshore wind is more realistic. Consequently, a main take-away is that the creation of a wind and solar based electricity grid with green hydrogen as a balancing agent is feasible. The results of this research gave rise to several recommendations. Firstly, renewable energy generation should be maximized using the full scope of different available techniques (not only focusing on offshore wind). Second, different decarbonization pathways other than offshore wind green hydrogen should be explored to account for process industry feedstocks. Third, the government should work closely together with other North Sea-bordering countries in order to make the best use of the available space. Fourth and final, efforts should be steered towards maximizing the wind energy potential of the Dutch North Sea, which is ideally suited for wind energy generation and should therefore be used in the best way possible.

Design and development / Respiratory distress syndrome (RDS) is a major cause of mortality and long-term morbidity annually affecting 14% preterm infants worldwide. Therapies have been developed to overcome this common disorder; however, limitations exist with these treatments that often lead to complications including bronchopulmonary dysplasia (BPD). One approach to address RDS is to implement a microfluidic oxygenator that serves as a respiratory support system for preterm neonates while the lungs fully develop, extra-uterine. This artificial lung assist device (LAD) is characterised by its non-invasiveness (given that it is connected via umbilical vessels), pumpless configuration, ambient air operation, portability and low priming volume. Furthermore, the LAD is formed by single oxygenator units (SOU) that are stacked in a parallel array which allows for usage on different body weights. The objective of this thesis is to design an electrochemical system to provide an in-situ enriched O2 environment able to supply 1.9 ml O2/min for use in the SOU while maintaining the simplicity of operation of the oxygenator. An inexpensive, electrically powered and compact device was envisioned allowing for a higher permeation flux to fully oxygenate the blood. Moreover, the system would be easy to manufacture, low maintenance and avoid the risk of gas contamination. In the initial work, different designs of electrolytic cells were developed and tested. The two- chamber design connected by a gel membrane showed an O2 production 10 times higher than with previous designs with 42 mg O2/L. Subsequently, different supporting electrolytes were tested. NaOH demonstrated a better performance and no degradation of the electrode in contrast to NaCl and Na2SO4. Stainless steel mesh (SSM) and graphite sheet electrodes were then tested; it was observed that stainless steel produced 3.4 times more dissolved oxygen (DO) than graphite with 28.3 mg O2/L. Experimentation with electrolysis of water showed that the DO in water reached stability 3 min after the electrolysis process was initiated measuring a change of DO of 29 mg/L at 3 A. Furthermore, an active oxygenation (AO) system was developed for in-vitro experiments via electrolysis of water and compared to a passive oxygenation (PO) system exposing blood to enriched O2 air and ambient air, respectively. It was demonstrated that AO provided 300% greater oxygenation to blood than PO. The electrolysis chamber designed for the microfluidic oxygenator allows the oxygenator to maintain its essential characteristics of simplicity and low cost while increasing the rate of oxygenation of blood. Preterm neonates suffering from RDS need an artificial lung that can partially support the oxygenation of their blood. Thus, combining the oxygenator with the O2 generation in-situ system enables a greater blood O2 uptake of 300% making possible the development of an efficient artificial lung. / Thesis / Master of Applied Science (MASc)