Selective Hydrogen Oxidation Catalyst for Reduced Startup/Shutdown Degradation in Low Temperature Fuel Cells

In this study, we are reporting for the first time clear evidence that Ir-based electrocatalysts are feasible alternatives to state-of-the-art Pt/C anode catalysts for PEMFC applications. While Ir/C has almost the same hydrogen oxidation activity as Pt/C, so that only minor voltage penalties are observed in H2/air performance curves (<20 mV at 1.5 A/cmgeo2 at 0.1 mgmetal/cm2), its oxygen reduction activity is substantially lower. Therefore, a replacement of Pt/C with Ir/C anodes would be expected to result in lower startup/shutdown (SUSD) damages. It will be shown that indeed 3-fold lower SUSD degradation rates are obtained with Ir/C compared to Pt/C anodes.