Modeling of the mixed potential in hydrogen peroxide-based fuel cells

• A model is developed for the study of the mixed potential at the cathode of H2O2-based fuel cells.
• The coupled mass/charge transport and electrochemical reactions are considered.
• The mixed potential associated with H2O2 oxidation appears at low current densities.
• The largest potential loss due to the HPOR occurs under the open-circuit condition.
• An increase in the reactant concentration leads to a decrease in the potential loss.

A one-dimensional mathematical model is developed for the study of the mixed potential associated with the hydrogen peroxide oxidation reaction (HPOR) at the cathode of hydrogen peroxide-based fuel cells. The complicated physicochemical processes, including mass transport, charge transport, and three simultaneous electrochemical reactions (the hydrogen peroxide reduction, hydrogen peroxide oxidation, and oxygen reduction reactions) are considered. The model is experimentally validated and shows good agreement with the literature experimental data. The model is then applied to the study of the mixed potential by varying the current density. It is found that the largest potential loss due to the HPOR occurs under the open-circuit condition (OCC), and the potential loss decreases with the superficial current density. In addition, the numerical results suggest that under the OCC, an increase in the concentrations of hydrogen peroxide and H+ ions leads to a decrease in the potential loss, but an increase in the hydrogen peroxide decomposition rate and the oxygen evolution rate.