Characterization and degradation study of an ePTFE reinforced polymer electrolyte membrane for PEM fuel cells applications

According to the International Energy Agency, global energy consumption is expected to increase more than 28% by 2040. The need of a green and sustainable energy transition, to feed the increasing energy demand while avoiding climate change, must be a priority for our society. Fuel Cells (FC) are promising green technologies appliable to different sectors, that are able to convert chemical energy directly into electricity, avoiding pollutants and CO2 production. In this scenario, Polymer Electrolyte Membrane Fuel Cells (PEMFCs) are hydrogen-fed, low temperature FCs suitable for the mobility applications, with the potential to contribute at the decarbonization of the transportation sector, together with hybrid and electric veichles. Many automotive companies are now investing into Fuel Cells research and some of them, such as Toyota and Hyunday, already have their FC-based veichles on the market. While PEMFC engines have already reached good performance levels, comparable to those of Internal Combustion engines, the main issue is associated with their durability. Reaching longer lifetime would be foundamental to adapt the technology to heavy duty applications and to make it more affordable and competitive on the market. Fuel Cells are subjected to many degradation processes, that reduce their operational lifetime. Among all the components, the electrolyte membrane seems to be one of the most sensible to degradation. Several solutions have been proposed to improve the durability of the membrane, which is today based on Nafion polymer. This work aims at characterizing a Nafion based membrane containing a ePTFE reinforment layer that is supposed to enhance its durability, contrasting chemical degradation processes. The main properties of this membrane will be compared to those of a standard commercial Nafion membrane (Nafion 212). In the second part of the study, a chemical degradation process based on Fenton's reactions will be carried on the ePTFE reinforced membrane, in order to evaluate the performance losses associated with chemical degradation. Since this kind of chemical degradation is based on the interaction of Iron contamination with hydrogen peroxide (that is a by-product of the main PEMFC reaction), the aim is to evaluate how the amount of Iron impacts on degradation and to determine the concentration of Iron able to take the cell to its end of life.