Tuning metal structures and surfaces for selected electrochemical reactions

• Online Access: http://hdl.handle.net/2047/D20248809

To mitigate serious issues like climate change and depletion of fossil fuels, adapting to renewable energy technology as primary energy source is an expedient solution. Among all the available renewable energy technologies, electrochemical energy devices are the most viable option since they have no geographical restriction and have potential to meet the global energy demand. To establish modular and scalable electrochemical energy devices, it is important to have a fundamental understanding of electrochemical interfaces and the factors that influence the cost, durability and fuel flexibility in these devices. In this dissertation, various metal surfaces and structures have been investigated to study selected electrochemical reactions that are relevant to electrochemical energy devices such as fuel cells and electrolyzers. This work mainly focusses on two vital electrochemical reactions: 1) Oxygen Reduction Reaction (ORR), which is pertinent to fuel cells and alkaline electrolyzers for the application of oxygen depolarized cathode (ODC) and 2) Hydrogen Oxidation Reaction (HOR) which is important for anion exchange membrane fuel cells (AEMFCs) where overpotential losses from hydrogen side is the major cause of overall performance loss in alkaline systems. To minimize the requirement of platinum in these energy devices, several categories of catalysts such as non- platinum catalysts, non- precious catalysts and catalysts with ultra- low platinum loadings have been explored. Development of such low cost, high performance catalysts are especially required to achieve a sustainable global green economy.