Optimizing operating conditions and stability evaluation of Fe/Co-NC catalyst in proton exchange membrane fuel cell.

Among all Metal-Organic Framework (MOF)-based catalysts, the bimetal structures perform more desirable in stability and output current density in the oxygen reduction reaction. Nonetheless, their stability in practical fuel cell systems and the influence of operational parameters on their performance remain unexplored to date. In the initial phase of this study, the electrochemical activity of a bimetallic metal-organic framework (MOF)-based cathode catalyst, specifically Fe/Co-NC(10 h), was investigated using three-electrode tests. Subsequently, the performance of catalyst (MEA2) was investigated under varying operating conditions within a single cell. Optimized operating conditions were then employed to assess the stability of the cathode catalyst through constant voltage and cyclic voltammetry tests. The results indicated that the optimal operating temperatures, pressures, and relative humidity of cathode for MEA2 were 75 °C and 2 bar, and 100%, respectively. Notably, MEA2 exhibited only a 4.98% decrease in current after 20 h of operation at 0.55 V and maintained its stability over 2500 CV cycles. FESEM images were utilized to investigate the stability mechanisms of the catalyst following prolonged operation, and the findings were corroborated by EDX results.