On 3 September at 10.15 Silver Juvanen will defend his doctoral thesis “Non-precious metal catalysts based on biomass-derived carbon for electrocatalytic applications”.
Supervisors:
Assoc. Prof. Ave Sarapuu, Institute of Chemistry, University of Tartu
Prof. Kaido Tammeveski, Institute of Chemistry, University of Tartu
Opponent:
Dr. Dulce M. Morales, Engineering and Technology Institute Groningen (ENTEG), University of Groningen, The Netherlands
Summary:
The growing impact of climate change and the strong dependence on fossil fuels are making it increasingly important to shift toward renewable and carbon-neutral energy sources. At the same time, the rapid growth of wind and solar energy production and their intermittent nature has intensified the demand for efficient energy storage and conversion technologies capable of balancing the fluctuations in energy prices. For short-term energy storage, batteries are a practical solution. Rechargeable zinc–air batteries are very promising because they are cheaper and safer than commonly used lithium batteries. For long-term energy storage, renewable electricity can be converted into hydrogen via electrolysis and subsequently used in fuel cells to generate electricity. While proton-exchange membrane fuel cell technology is mature and is already commercially available, increasing attention has been directed toward anion-exchange membrane fuel cells (AEMFCs) as a potentially more cost-effective alternative. However, a major obstacle for the widespread deployment of both low-temperature fuel cells and zinc–air batteries is the need for expensive platinum group metal (PGM)-based catalysts. The aim of this doctoral thesis was to develop efficient PGM-free electrocatalysts for oxygen reduction and evolution reaction and to use them as catalyst materials in AEMFCs and air electrode catalysts in rechargeable zinc–air batteries. Nanostructured carbon-based catalysts were synthesized using glucose and rapeseed press cake as precursor materials and were thoroughly characterized using a combination of electrochemical and physicochemical techniques. The results obtained in this PhD thesis demonstrate that biomass-derived precursors can be used to produce highly active electrocatalysts with excellent performance in both AEMFC and zinc–air battery devices, highlighting their potential for practical energy conversion and storage technologies.
