Characterisation of Condition-Tolerant Fuel Cell Catalyst Layers

As fuel cells move from a research activity to actual vehicles there is an increasing demand for MEAs that perform well across a very wide range of conditions. This condition tolerance is strongly linked to the composition and structure of the catalytic layers which are built from a mixture of platinum on a carbon support and ionomer. The carbon support accounts for a significant amount of the volume of the layer and is crucial in determining the porous structure of the layer. We would like to investigate how the properties of different carbon supports transfer through to the catalytic layer. This would start with understanding the internal pore structure of the primary particles and the intra-particle porosity in the primary aggregates and agglomerates. The effect of differing catalyst preparations and treatments on the carbons would then be analysed to see how the addition of platinum particles and the processes involved affect the pores and surface chemistry of the carbon. Once these building blocks are understood, the analysis would be extended on to full catalyst layers where the effects of processing conditions and ionomer loading and type would be examined. This would be primarily focussed on bulk characterisation techniques such as gas sorption and mercury intrusion porosimetry with some support from 3D reconstruction where necessary. The aim would be to generate the necessary understanding to allow more appropriate carbon properties to be defined in order to generate condition tolerant catalyst layers.