Highlights
•
DMFC temporary degradation occurs both at the anode and at the cathode of a DMFC.
•
The main mechanism responsible for DMFC cathode temporary degradation is the formation of platinum oxides.
•
Interrupting the cathode air feeding in OCV determines platinum oxides reduction and cathode performance recovery.
•
Shortage of oxygen in cathode channel during the air break determines periodic hydrogen production at the anode electrode.