Exploring low cost elements based nanostructured electrocatalysts for sustainable energy conversion

Abstract

newlineAbstract: As the global demand for energy continues to rise, coupled with concerns about newlineclimate change and resource depletion, there is a growing urgency to develop efficient and newlineenvironmentally friendly energy conversion technologies. One promising avenue is newlineelectrocatalytic energy conversion, wherein catalysts are employed to facilitate electrochemical newlinereactions which are involved in fuel cell and energy storage batteries that convert chemical newlineenergies of fuels like hydrogen and oxygen into usable forms of energy, such as electricity. newlineThese electrocatalytic energy conversion technologies hold the potential to offer a global newlinesolution towards the energy crisis by integrating intermittent and geographically specific newlinerenewable energy sources. Conventionally, noble metals like platinum and iridium have been newlineutilized as catalysts due to their exceptional catalytic activity. However, their scarcity and high newlinecost hinder their large-scale adoption. newlineThis thesis focuses on an alternative approach by exploring nanomaterials composed of newlineearth-abundant elements as catalysts for electrocatalytic reactions. Along with choosing newlinesustainable materials for the production of highly efficient electrocatalysts, bringing newlinesustainability into the production protocol also has been emphasized in this thesis. Therefore, newlinenanomaterials studied in several projects were fabricated using cost-effective synthetic newlinepathways, making them an attractive option for scalable energy conversion technologies. The newlinefirst part of the thesis focused on the sustainable production of atomically dispersed first-row newlinetransition metals over nitrogen-doped carbon nanosheets (M-N-C) and deriving governing newlinefactors behind achieving atomic dispersion instead of nanoparticle formation, utilized for newlineelectrocatalytic ORR and OER. We further quantify and explain for each metal a negative mass newlinebalance originating from anomalous mass loss of both metal and carbon content, and a massive newlinereconstruction of the carbon backbone catalyzed by the very metal. In the nex