Doctoral defence: Yogesh Kumar “M-N4 macrocycle-based catalysts for electrocatalysis of oxygen reduction and oxygen evolution​​​​​​​“

On 21 December at 10:15 Yogesh Kumar will defend his doctoral thesis “M-N4 macrocycle-based catalysts for electrocatalysis of oxygen reduction and oxygen evolution” for
obtaining the degree of Doctor of Philosophy (in Chemistry).

Supervisors:

Professor in Colloidal and Environmental Chemistry Kaido Tammeveski, University of Tartu

 Elo Kibena-Põldsepp, University of Tartu

Research Fellow in Colloidal and Environmental Chemistry Srinu Akula, University of Tartu

Opponent:

Justus Masa, Max Planck, Institute for Chemical Energy Conversion,  (Germany)

Summary

Bifunctional oxygen electrocatalysts have emerged as pivotal components in a broad spectrum of electrochemical devices, playing a crucial role in facilitating the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). These reactions are crucial in various electrochemical energy conversion and storage technologies, including fuel cells, metal-air batteries and water electrolysers, thereby aiding in the transition away from reliance on fossil fuel-based energy systems. The aim of this doctoral thesis was to explore the electrocatalytic performance of a range of first-row transition metal-based materials for bifunctional oxygen electrocatalysis. These materials encompassed bimetal-doped carbon nanotubes, catalysts doped with metal phthalocyanines on various commercial carbon supports and polymer framework-derived carbon materials doped with transition metals. The specific focus of this investigation was to elucidate the influence of various factors on the ORR and OER activity. The key objective was to develop better electrocatalysts and to establish relationships between their structure and properties. These materials were employed as cathode catalysts in anion-exchange membrane fuel cells and as air electrodes in zinc-air batteries, demonstrating exceptional performance with several of them matching or even surpassing the performance of commercial noble metal-based catalysts. This comprehensive research spanning from the synthesis of novel catalyst materials to the thorough analysis of their electrochemical behaviour, strives to make a meaningful contribution to the dynamic field of electrocatalysis.

Defence can also be followed in Teams.