Evaluation of Low and High Surface Area TiO₂ and Al₂O₃ Metal Oxides-Carbon Hybrids in Terms of Polymer Electrolyte Membrane Fuel Cell Catalyst Support.

Abstract

Support materials are of great interest in order to improve the activity and stability of the polymer electrolyte membrane fuel cell (PEMFC) catalysts. Metal oxides have been reported as promising support materials due to their excellent mechanical resistance and high stability against corrosion emerging at acidic and oxidative environment. In this study, high (250 m₂/g) and low (45 m₂/g) surface area mesoporous TiO₂ and high (220 m₂/g) and low (30 m₂/g) surface area mesoporous Al₂O₃ were investigated as an alternate cathode catalyst support materials for PEMFCs. These semiconducting TiO₂ and Al₂O₃ metal oxides were combined with the carbon black (Vulcan XC 72) at different mass ratios in order to preserve electrical conductivity of catalyst support a certain extent. Pt and TiO₂/C and Pt and Al₂O₃/C catalysts were prepared by means of Pt reduction on support materials via microwave irradiation technique. The as-prepared catalysts were characterized with some physicochemical and electrochemical analyses. The results reveal that two surface areas TiO₂ and Al₂O₃ support materials differ from each other in terms of fuel cell performance and high surface area TiO₂/C (25:75) hybrid supported Pt catalyst gave the best performance.