(Invited) Quantifying the Distribution of Catalyst Support Carbon Corrosion

Abstract

Catalysts for proton exchange membrane fuel cell (PEMFC) electrodes are commonly dispersed on granular carbon supports to maximize performance. The carbon material will rapidly oxidize if exposed to high potential excursions, so PEMFC systems need to minimize these conditions such that lifetime damage is kept low. Diagnostic methods are used to evaluate operating conditions and mitigation strategies. This presentation first reviews several diagnostic approaches to quantify carbon support corrosion (Table). While cross-section electrode thickness is the most reliable indicator of support loss, other methods are desirable for higher sensitivity, greater convenience, or non-destructive sample throughput. However, these alternative methods generally involve greater uncertainty and more convoluting factors. Workarounds for these complications will be discussed, along with the application of a current distribution board for estimating carbon loss across the active area of a cell. The presentation concludes with examples of support corrosion distribution observed in automotive-competitive fuel cells (Figure). Figure 1