When looking at the high current density region of the
Beyond monitoring the degradation mechanisms of the PtM/C samples in the various AST, of prime importance was to link the observed degradations to the change of oxygen NVP-BVU972 reaction performance of the electrocatalysts. For that purpose, ultramicroelectrodes with cavity (UMEC) of the electrocatalysts were tested with the same electrochemical protocol (same characterizations, same AST) in the dry cell. We emphasize at this point that the UMEC data obtained in the dry cell must be viewed as a means to compare a given electrode prior/after the AST, more than a manner to measure with precision the ORR kinetics parameters of the electrocatalyst immobilized in the UMEC, as put into evidence by the discrepancies between the initial SA values (Table 3) measured for different UMECs.
Specific activity (SA in μA/cm2Pt) of the Pt/C and Pt3Co/C electrocatalysts before and after the various AST performed in the dry cell (Ar atmosphere during the AST).AST protocolSA @ 0.90 VSA @ 0.85 V0.1–0.9 V0.6–0.9 V0.1–0.9 V0.6–0.9 VSampleBeforeAfterBeforeAfterBeforeAfterBeforeAfterPt/C22.214.171.124.88.415128.0Pt3Co/C1711119.056323023Full-size tableTable optionsView in workspaceDownload as CSV