In a PEM fuel cell, the anode catalyst facilitates the oxidation of hydrogen molecules into protons and electrons: 2H2 â 4H+ + 4e- At the cathode, the catalyst aids in the reduction of oxygen molecules, combining them with protons and electrons to form water: O2 + 4H+ + 4e- â 2H2O These reactions are critical for the overall efficiency and performance of the fuel cell.
