Developing Reversal-Tolerant Anode for PEFCs by Introducing Iridium-Based Layered Structure

Abstract

The cell voltage reversal phenomena occurring at the anode was focused on for the purpose of extending the lifetime of PEFCs. In order to address both the carbon-based degradation and alloying-based degradation at the anode. Multifunctional layered anodes were proposed. Anodes were designed in order to separate the Pt/C and IrO2 layers. This approach successfully increased durability toward the carbon-based degradation. This is most likely because a water electrolysis reaction rather preferentially occurs at the IrO2 layer near the electrolyte membrane, leading to suppression of carbon corrosion reaction at the Pt/C layer. Regarding to the alloying-based degradation, contacting two layers of Pt/C and IrO2 lead to Pt-Ir alloying even though two layers were separately made. However, when two layers of Pt/C and IrO2 were completely separated by inserting the carbon layer, Pt-Ir alloying was totally avoided.