Supervisor: Mykhailo Vorokhta, Ph.D.
Proton exchange membrane fuel cells (PEMFCs) fed by hydrogen are expected to become a clean power source for vehicles in the near future. So far the main obstacles to the commercialization of fuel cells the high cost of platinum that is the most effective catalyst for PEMFC on the both cathode and anode sides. Search for new materials able to replace platinum or at least decrease its amount in the fuel cell is very intensive these days. The easiest way how to develop a new catalyst for PEMFC is to understand processes taking place on its surface during operation. Accordingly, utilization of in-situ/operando techniques that give us valuable information about the catalyst layer under operational conditions is of great importance. Near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS) is a powerful technique that makes possible chemical investigation of different catalyst layers in the presence of gases and vapours providing information on catalyst oxidation state and reaction intermediate species that appear on the surface. By having this information one can find a way how to develope an effective and cheap catalyst.
The dissertation work will focus on materials much cheaper than pure Pt, however relevant for PEMFC applications. Ceria based catalysts doped with noble metals (Pt, Au, Pd…) will be studied by NAP-XPS, as promising highly active anode catalysts. Different platinum based bimetallic and trimetalic catalysts will be considered and investigated for the cathode side. Together with NAP-XPS technique other powerful surface science characterization techniques such as low energy electron diffraction (LEED), scanning tunnelling microscopy (STM) and synchrotron radiation photoelectron spectroscopy (SRPES) are planned to be used in this work.