Lifetime Test of Pt-Pd/C PEMFC Cathode Catalyst

Durability of the catalysts is a major problem that hindering the commercialization of proton exchanges membrane fuel cells (PEMFCs). Recently, much attention has been paid to Pt-Pd catalyst supported on carbon due to its better performance as oxygen reduction reaction catalsyt. Here we presented a durability test result of the Pt3Pd/C catalyst and compared with a commercial Pt/C catalyst.\nThe I-V curves are presented in Fig.1. The initial performance was close to each other. However, after 400 hours operation under dynamic loading, the Pt3Pd/C catalysts showed very little degradation especially in the low current density region which was recognized as the kinetically controlled region. The changes of electrochemical active area derived from the CV are shown in Fig.2. After 400 hours, 37% of the initial ECA was lost for Pt3Pd/C while 58% for Pt/C. EIS was also adpapte to monitor the performance change of the catalysts. After the durability test, the diameter of the EIS arc for Pt/C increased largely when compared to the beginning of the test. However, the Pt3Pd/C only changed a little.\nAll the findings demonstrated that Pt-Pd/C catalyst has a higher durability than conventional Pt/C catalyst. TEM &XRD characerization revealed that the Pt-Pd/C catalyst has a larger particle size than Pt/C. The reason may ascribe to electronic modification effect, which improves both activity and durablity of the nano sized catalyst.