Metal Oxides for Hydrogen Activation and Sustainable Chemical Conversions

Our green, renewable future remains an unsatisfyingly distant reality. Although we are taking actions to suppress anthropogenic harm to the natural world, there is scientific consensus that radical changes are needed today to avoid significant ecological and climate damage. In this direction, a hydrogen-based economy has been proposed as a sustainable alternative to a fossil-based economy. Hydrogen is receiving such attention because it has the potential to be carbon-free, producing only water when used as a fuel. However, the production of hydrogen is currently tightly linked to fossil fuels, and fossil-free methods remain under-developed. Sourcing hydrogen from water and renewable electricity has been proposed as a significant opportunity for making positive steps towards a more sustainable future. This dissertation focuses on the development of catalytic schemes that combine water electrolysis and hydrogenation chemistries through mediated hydrogen transfers. The specific approach uses metal oxide hydrogen bronzes to electrocatalytically activate hydrogen from water and then supply it for general hydrogenation chemistries. It is worth noting that the chemical industry is the leading consumer of hydrogen, and it will remain so for many decades. This work is driven by the hypothesis that these bronzes offer fine control over the activity of hydrogen and can be tuned to accommodate specific hydrogenations. Research herein includes fundamental studies of the thermodynamics, transport phenomena, and kinetics of hydrogen intercalation into metal oxides. Additionally, a mediated hydrogenation using tungsten oxide is demonstrated. Overall, this research offers foundational knowledge of bronze-mediated hydrogenations and presents a means for environmentally benign hydrogen utilization, bringing us closer to a sustainable chemical industry