Depressing the H₂O₂ generation rate to enhance the durability of the hydroxide exchange membrane fuel cells

The hydroxide exchange membrane fuel cells (HEMFCs) are considered promising due to their potential low cost. However, their unsatisfied stabilities hinder the widespread application of HEMFCs. Here, we confirm that the in-situ generated H₂O₂ takes serious influence on the degradation of the HEMFCs, and the more H₂O₂ generated the worse HEMFC stability. A mixed titanium oxide and ruthenium oxide doped by niobium (TiO₂-RuO₂-Nb₂O₅ (TRNO)) is synthesized and used as support for Pt to replace the commonly used carbon. The Pt/TRNO catalyst shows low H₂O₂ yield when used as oxygen reduction reaction (ORR) catalyst. By using Pt/TRNO as cathode, the fabricated HEMFC shows outstanding long-term durability. The cell voltage only decays 2.2%, discharging at a constant current density of 500 mA·cm⁻² for 170 h, with a low decay rate of 76 μV·h⁻¹. These findings reveal that H₂O₂ yield is a key factor leading to the degradation of HEMFC, and the HEMFC stability could be improved by using the oxide supported catalysts with low H₂O₂ yield.