Improved operating strategies for the optimization of PEMFC system performance

The formation of platinum oxides at PEMFC working cathode potential is one of the main sources of reversible performance loss during operation as this mechanism passivates active surface. Therefore, promoting the electrochemical reduction of these oxides during operation is a solution to increase performance and mitigate reversible losses related to this phenomenon. Thus, a feasible solution to achieve this result in a PEMFC stack and system is to apply frequent and short operating phases with reduced air supply at the cathode. This procedure, called "air starvation" enables the decrease of cathode potential from nominal potential to approximately 0 V vs. RHE, promoting the electrochemical reduction of platinum oxides. This study focuses on the optimization of recovery parameters, first at small single cell scale and then at short-stack scale with air starvation procedure.