Doctoral defence: Huy Qui Vinh Nguyen "Development of Carbon Supported Pt–CeO2 Catalysts for Proton Exchange Membrane Fuel Cells"

On 16. August at 11:15, Huy Qui Vinh Nguyen will defend his thesis "Development of Carbon Supported Pt–CeO₂ Catalysts for Proton Exchange Membrane Fuel Cells".

Supervisor:
lector Heili Kasuk, Institute of Chemistry, University of Tartu
professor Enn Lust, Institute of Chemistry, University of Tartu
professor Jaak Nerut, Institute of Chemistry, University of Tartu

Oponent: 
Assistant Professor Jonathan Quinson, Aarhus University, Denmark

Summary
Hydrogen technology and hydrogen-based transportation are undoubtedly indispensable parts of the global economy. Hydrogen plays a crucial role in many industrial applications. As a notable development in May 2024, the CEO of Tesla Inc., Elon Musk, fired 500 Supercharger Team employees. This move speaks volumes about Tesla’s changing vision for electric vehicles and raises the question of whether they also will transition to hydrogen car technology.

The Toyota Mirai hydrogen car’s interior space is smaller than that of a typical car with an internal combustion engine. This is due to the low volumetric energy density of hydrogen compared to petrol. The interior space volume issue can be solved by the use of other fuels in electric cars, such as methanol or ethanol, because the energy stored in one litre of methanol or ethanol equals 50% (in methanol) and 70% (in ethanol) of the energy of one litre of petrol and is respectively 27 and 35 times higher than that of hydrogen at a pressure of 70 bar. The heart of an electric car using methanol fuel is a direct methanol fuel cell (DMFC), which converts the chemical energy of methanol into electricity.

The University of Tartu has a clear vision for the future of green energy. Therefore, this study was conducted to develop the Pt-CeO₂/C catalysts for DMFC. Since the performance and stability of the DMFC anode catalysts are significant obstacles to the commercialisation of DMFCs, the breakthrough Pt–CeO₂/C anode catalyst that is highly active and as stable as the best Pt–CeO₂/C catalysts reported by other researchers was developed. On the laboratory scale, the methanol oxidation activity of the catalyst synthesised reached 0.86 at an electrode potential of 0.5 V and 201 at an electrode potential of 0.85 V. To achieve this result, the synthesis method of Pt and CeO₂ nanoparticles was optimised using various approaches. The structure and electrochemical performance of the catalysts were thoroughly investigated to elucidate the structure-induced effects on the catalytic activity. The current thesis explains many factors of the synthesis that affect the methanol oxidation activity of the catalysts. A novel DMFC catalyst carbon support superior to commercial carbon was also developed.