Fuel Cell Durability Study of PGM-Free ORR Catalysts

Abstract

The focus of LANL’s platinum group metal (PGM)-free catalyst program has been on the improvement and implementation of high-performing and durable cathode catalysts for polymer electrolyte fuel cells (PEFCs). Over the last decade, fuel cell performance of PGM-free catalysts gauged by the current density at 0.9 V iR-free in H2-O2 at 1.0 bar has been increased as much as three times (from 12 to 36 mA/cm2). While in durability aspect not much of progress as well as understanding has been achieved.Fuel cell durability of the catalysts is critical in particular for practical application of the catalysts. Recently ElectroCAT, US DOE supported PGM-free catalyst consortium, proposed the durability test protocol (draft) for PGM-free catalysts. In this presentation, we will report catalyst durability tested following the ElectroCAT-proposed protocol for several catalysts. In conjunction with characterization tools such as cyclic voltammetry, impedance measurement, STEM, x-ray absorption spectroscopy (XAS), and Mössbauer spectroscopy, we will discuss the possible degradation mechanisms as well as pathways to improve the durability of PGM-free catalysts. Acknowledgements This research has been supported by DOE Fuel Cell Technologies Office through Electrocatalysis Consortium (ElectroCat). Microscopy was performed as part of a user project supported by Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences, a DOE Office of Science User Facility.