Corrosion of carbon supports at cathode during hydrogen/air replacement at anode studied by visualization of oxygen partial pressures in a PEFC-Start-up/shut-down simulation

▶ Start-up/shut-down of a PEFC was simulated by exchanging H2 and air at the anode. ▶ Dye film was used to visualize pO2 at the anode during the H2/air exchange. ▶ Gas exchange rate was lowered by protons produced by carbon corrosion at the cathode. ▶ After degradation, oxygen was consumed mainly in the middle of the MEA. ▶ STEM images of the catalyst layer showed holes near the inlet and outlet of the cell.