Carbon oxidation corrosion of an FeNC catalyst in PEMFC

Degradation mechanism of FeNC electrocatalysts in PEMFCAt present, the increasing demand for renewable sources along with the requirement of reduction of carbon dioxide emissions is one of the greatest challenges for the scientific community. The intermittency of this type of source is the biggest limit to their widespread, although it could be solved by hydrogen. This element is considered one of the most promising means for storing energy and the improvement of the technology related to this element can be the key for the energetic transition. Amongst all, proton exchange membrane fuel cell (PEMFC) is the most hopeful technology to exploit Hydrogen as fuel to produce electrical power. However, the main problem related to this device's commercialization is the high production cost, especially the catalytic component. PEMFC catalysts are mainly composed of Platinum group metal (PGM), elements characterized by incredible activity and stability, as well as scarcity and expensiveness. The seek for PGM-free is pivotal for the replacement of Pt in fuel cells. Among them, FeNC are considered the most auspicious catalysts able to reach performance comparable to the ones of PGM catalysts. However, the actual efficiency of these catalysts is insufficient and the main limit can be traced in their low stability, in turn, due to degradation mechanisms that take place at the catalytic level. The main degradation mechanisms are carbon corrosion and demetallation and, according to the work proposed in the literature, they became relevant at high (over 0.9 V) and low (below 0.7 V) potentials respectively. This thesis aims to go deep into the comprehension of the degradation mechanisms that happen in these potential windows for a FeNC-type catalyst. This research is conducted by analyzing the products formed at the cathode side of the fuel cell with a quadrupole mass spectrometer (QMS), evaluating activity loss depending on the behavior of CO2, linked to the degradation of catalyst material.