Rotating disc electrode as a method for measuring the activity and stability of iridium-based oxygen evolution reaction electrocatalystsStojanovski, Kevin (Avtor) Gaberšček, Miran (Mentor) oxygen evolution reactioniridiumtitanium oxynitridecatalyst stabilityproton exchange membrane devicesDuring past decades, fossil fuels have been a crucial driving force for the growth of society and all of the most important industries. First as coal for the steam engines and the beginning of the industrial revolution, up to modern days where they still represent the most used fuel for all aspects of modern life. However, knowing the impact that they have on our world, we must consider transitioning to more renewable and sustainable energy sources. Storing energy in the form of hydrogen has many benefits, the most prominent of which is the lack of emission of carbon dioxide upon its consumption as fuel. A key piece to utilizing this stored energy is the polymer exchange membrane fuel cell (PEMFC), a device that could provide localized electrical power using hydrogen as its primary fuel and producing only water as its waste. However, very similar devices can also be used for the production of hydrogen utilizing electrolysis. Here we explore iridium nanoparticles supported on high surface titanium coating that is covering a base layer of carbon [2] for the anode, to promote the oxygen evolution reaction – the counter-reaction needed for effective hydrogen evolution. We demonstrate catalyst support based on titanium oxynitride that provides a high surface area on which iridium nanoparticles can be supported. Such a combination of materials increases the efficiency of electrochemical reaction while lowering the catalyst amount. Furthermore, by performing a number of accelerated degradation protocols we show that the titanium oxynitride coating over the surface of the carbon substrate allows for stable support that can withstand the harsh conditions found during the oxygen evolution reaction. We also highlight the many problems with benchmarking new catalysts and supports for OER, using the rotating disc electrode (RDE). In this thesis we are examining the following specific experimental aspects i) substrate electrode material, ii) catalyst loading iii) catalyst long term stability iv) catalyst ink preparation, and v) activation protocols together with electrode prehistory. All of those play a crucial role when using RDE for evaluating OER electrocatalyst.20202020-07-17 10:50:01Magistrsko delo/naloga117594VisID: 7521COBISS_ID: 23904515sl