Modification of Vulcan XC-72 for Enhanced Durability of PEMFC Catalyst Layer

Abstract

A series of SiO2 modified Vulcan XC-72 support materials were prepared to investigate the effect of silica modification on the durability of the catalysts layer of Polymer Exchange Membrane Fuel Cells (PEMFC). XRD, TGA, BET, DLS, EDX and TEM were used to examine structural and microstructural properties. The performance of the catalysts layers were evaluated using a single cell operating at 60 degrees C under fully humidified H-2 and O-2 purge. Electrochemical Impedance Spectroscopy (EIS) experiments were carried out to observe the impedance behavior of the MEAs. The MEAs were cycled between 0.6V to 1.2V for 24 hours at 20 mV/s (1440 cycles) under hydrogen and nitrogen purge to conduct Accelerated Durability Tests (ADTs). The modification of Vulcan XC-72 was found to be an effective way to improve both the performance and the durability of the catalyst. The MEA with 22.9 wt% SiO2 content showed 13 times less performance loss than that of the MEA prepared with commercial catalyst after ADTs.