Catalyst layer doped with phosphotungstic acid for degradation mitigation in Polymer Electrolyte Membrane Fuel Cells

The aim of this study was to enhance durability and performance of Polymer Electrolyte Membrane Fuel Cells (PEMFCs) for transportation application. A modified catalyst coated membrane (CCM) with phosphotungstic acid (PTA) in catalyst layer was fabricated using a heating ultrasonic-spray method, and durability study of both the modified CCM and traditional CCM was carried out according to the DOE CCM/stack durability protocol. During the accelerated stress test of CCM durability, cyclic voltammetry, polarization curves, linear sweep voltammetry and electrochemical impedance spectroscopy were employed for diagnosis of the CCM performances. The experimental results indicate that the power density of the modified CCM decreased only 14% while the traditional CCM decreased 33% after 100-h aging time, which confirms that addition of PTA in the catalyst layer of CCM is an effective way to improve the durability for CCM attributed to the enhancement of intermediates removal and the increasing of proton transfer channels by using the PTA excellent properties, both redox property and proton conductivity.