Study of Oxide Supports for PEFC Catalyst

Polymer electrolyte membrane fuel cell (PEFC) systems for fuel cell vehicles (FCVs) require both performance and durability. Carbon is the typical support material used for PEFC catalysts. However, hydrogen starvation at the anode causes high electrode potential states (e.g., 1.3 V with respect to the reversible hydrogen electrode) that result in severe carbon support corrosion. Serious damage to the carbon support due to hydrogen starvation can lead to irreversible performance loss in PEFC systems. To avoid such high electrode potentials, FCV PEFC systems often utilize cell voltage monitor systems (CVMs) that are expensive to use and install. Simplifying PEFC systems by removing these CVMs would help reduce costs, which is a vital part of popularizing FCVs. However, one precondition for removing CVMs is the adoption of a durable support material to replace carbon. For this reason, tin oxide and titanium oxide were examined as cathode and anode support materials, respectively, since these materials are more stable under high potentials than carbon. Membrane electrode assemblies (MEAs) with titanium oxide- and tin oxide-supported platinum (Pt) catalysts were prepared and compared with conventional carbon-supported Pt catalysts. The results of this study found that MEAs using these metal oxide supports achieved equivalent performance to conventional carbon-supported Pt catalysts. These metal oxide supports were also more durable under a high potential (1.3 V) than carbon-supported Pt catalysts. © 2017 SAE International.