Systems Strategies to Mitigate Carbon Corrosion in Fuel Cells

Abstract

The oxidation of carbon used as catalyst support in state-of- the art fuel cells is a serious decay mechanism that must be mitigated in order to achieve acceptable performance stability. Although the corrosion of carbon is certainly not a new concern for fuel-cell developers, a number of fairly recent developments have brought this issue to the forefront. These concerns include the unique operating conditions of transportation applications, the discovery of a mechanism that results in higher-than-expected potentials (i.e., the reverse- current mechanism), and the use of certain materials (e.g., high surface area carbon supported catalysts with high Pt mass fractions). Since improvements in catalyst-support stability typically comes at the expense of performance (and/or cost), and these improvements alone will be insufficient for many applications, system-mitigation strategies are required. A number of system strategies that have been developed and demonstrated at UTC Power will be described.