Nano to Micro Scale Characterization of Water Uptake in The Catalyst Coated Membrane Measured by Soft X-ray Scanning Transmission X-ray Microscopy

We describe a method of quantitative mapping the water content in the catalyst coated membranes (CCM) of proton exchange membrane (PEM) fuel cells with high spatial resolution (~30 nm) using soft X-ray Scanning Transmission X-ray Microscopy. Detailed component chemical maps of CCMs at different environmental conditions (relative humidity (RH)) were generated from O 1s optical density measurements by fitting to the soft X-ray absorption …