Standardized protocols for evaluating platinum group metal-free oxygen reduction reaction electrocatalysts in polymer electrolyte fuel cells

Abstract

Platinum group metal (PGM)-free electrocatalysts for the oxygen reduction reaction at the polymer electrolyte fuel cell cathode have shown substantial improvements in activity—especially those derived from transition metals, nitrogen and carbon. However, their stability and durability remain insufficient. A key to enabling future improvements and performance comparisons lies in the development of test protocols that are relevant to the operating conditions of the fuel cell cathode, can be completed within a reasonable time and are ubiquitously adopted. Here we propose and validate such protocols, designed with special attention to typical catalyst degradation mechanisms of PGM-free catalysts. The results of the cross-laboratory validation study using two different catalysts attest to the strength and feasibility of the proposed approach. We hope that the information provided here can serve as a broad and effective platform for assessing the performance and durability of PGM-free catalysts for polymer electrolyte fuel cells. The development of platinum group metal-free catalysts for the oxygen reduction reaction is central to the implementation of fuel cell technology. Here the authors introduce and analyse a dedicated protocol for platinum group metal-free oxygen reduction reaction catalysts to assess their activity and durability under relevant working conditions.