Supervisor: Mgr. Yurii Yakovlev, Ph.D.
Status: Available
Abstract:
Hydrogen fuel cells are an efficient source of carbon emission-free energy, which because of its versatility can be found in many applications. Performance of fuel cells relies on the activity of catalysts, typically based on platinum group metals (PGM). In order to make this technology commercially viable usage of the PGMs should be substantially decreased. Though present-day low PGM catalysts show a promising performance, they are still susceptible to deactivation or poisoning by impurities, which are normally present in hydrogen and air. This is why the study of catalyst poisoning and development of poison-tolerant materials is extremely important for the production of highly reliable fuel cells.
This work will be focused on the study of poisoning mechanism on model catalysts and synthesis of poison-tolerant catalyst nanoparticles. Model thin-film catalysts will be prepared by magnetron sputtering technique. The poisoning process on model catalysts will be investigated by near ambient pressure photoelectron spectroscopy (NAP XPS) and by rotating disk/rotating ring disk electrode (RDE/RRDE) techniques. Results of the model study allow us finding the most promising catalytic material which will be synthesized in form unsupported/supported nanoparticles. A deeper understanding of the poisoning mechanism on model systems with different structures will be crucial for the design of catalyst, revealing the best architecture among alloys, core-shell structures, and bimetallic nanoparticles. Catalyst nanoparticles will be prepared by chemical methods. Structure and morphology of synthesized nanoparticles will be studied by electron microscopy SEM/TEM and photoelectric spectroscopy (XPS). Activity and performance of the catalysts in the presence of poisoning species will be assessed in the electrochemical cell using RDE/RRDE techniques. Finally, catalyst nanoparticles will be tested in the fuel cell.
The main goal of this work is the establishment of the relationship between composition, structure, and morphology of catalyst nanoparticles and their long-term performance in the presence of poisoning species.