(Digital Presentation) Small Angle X-Ray Scattering Studies Investigating the Degradation of Electrocatalysts

Abstract

In the presentation, the application of small angle X-ray scattering (SAXS) in the investigation of degradation phenomena for electrocatalysts is discussed based on recent examples from my work group. In contrast to local methods such as identical location (IL) microscopy1, SAXS probes a microscopic volume of a catalyst film providing representative data for the catalyst. Furthermore, the method can be coupled to operando measurements or to ex situ measurements in gas diffusion electrode setups2. It is demonstrated that the analysis of SAXS data leads to reliable information of change in mean particle size of the catalysts as function of the applied degradation protocol, however, that a proper measurement and control of a background is essential due to the concomitant degradation of the support material. Keeping this in mind SAXS can play a crucial role for not only elucidating and rationalizing degradation phenomena, but also for the testing of concepts for new electrocatalysts with improved stability. Arenz, M. & Zana, A. Fuel cell catalyst degradation: Identical location electron microscopy and related methods. Nano Energy 29, 299–313 (2016).Schröder, J. et al. A New Approach to Probe the Degradation of Fuel Cell Catalysts under Realistic Conditions: Combining Tests in a Gas Diffusion Electrode Setup with Small Angle X-ray Scattering. J. Electrochem. Soc. 167, 134515 (2020).