S T R U C T U R E O F M A T E R I A L S
S C I E N T I F I C H I G H L I G H T S
1 3 2 H I G H L I G H T S 2 0 2 2 I
Fig. 125: a) SAXS scattering data were fitted to determine
(b) the mean particle sizes and standard deviations of
the log-normal distributions of the two size populations of the bimodal catalyst at
the depth closest to the electrolyte-catalyst. The mean particle sizes were used during the Rietveld
refinement of (c) the WAXS diffraction pattern
to determine (d) the phase fractions of both size
populations of the depth closest to the electrolyte- catalyst interface and the middle depth. The data
points shown for a negative AST number were recorded
after electrolyte insertion (before electrochemical
contact). e) The operando SAXS and WAXS results
were combined, proposing a depth-dependent degradation
mechanism. Adapted with permission from ACS Catal.
12, 2077-2085 (2022). Copyright 2022. American
Chemical Society.
Investigating the depth-dependent degradation of a bimodal Pt/C fuel cell catalyst
Combining operando small- and wide-angle X-ray scattering (SAXS, WAXS), the influence of simulated drive cycle conditions on catalysts for proton exchange membrane fuel cells (PEMFCs) was investigated. Depth-dependent scattering data reveal a complex degradation mechanism that depends on the distance between the catalyst nanoparticles and the electrolyte.
