The thin film-rotating disk electrode (TF-RDE) method is the standard method for screening the performance of electrocatalysts for polymer electrolyte membrane fuel cells (PEMFCs). It is fast and requires only small amount of catalysts, however, the measured activity not only depends on the intrinsic catalyst properties, but also ink and catalyst film properties, respectively [1, 2]. In addition, the RDE method has an inherent limitation of low reactant mass transport, which limits the accessible reaction rates and potential ranges. This limitation makes it difficult to predict the performances of the catalysts in membrane electrode assembly (MEA) where much higher mass transport is required and higher overpotentials are applied.

Recently, we introduced a new half-cell configuration aiming to bridge the gap between the RDE method and MEA, a gas diffusion electrode (GDE) setup [3, 4] that combines the strength of TF-RDE method and at the same time alleviates its weakness (i.e. low reactant mass transport).

In the presentation, the two approaches, TF-RDE and GDE measurements are compared and their weaknesses and strengths in measureing activity and stability of PEMFC catalysts discussed. Benchmark data and best practise guidlines are given.

[1] M. Inaba et al., Journal of Visualized Experiments, 2018, e57105

[2] M. Inaba et al., Journal of Power Sources, 2017, 353, 19-27

[3] G.K.H. Wiberg et al., Review of Scientific Instruments, 2015, 86 (2), 024102

[4] M. Inaba et al., Energy & Environmental Science, 2018, 11, 988-994