Advances in Structural Characterization Using Soft X-ray Scanning Transmission Microscopy (STXM): Mapping and Measuring Porosity in PEM-FC Catalyst Layers

Access of fuel and oxidant gases to the active catalyst sites in dispersive electrodes of polymer electrolyte membrane fuel cells (PEM-FC) is an important characteristic defining the performance of the whole catalyst coated membrane unit (CCM). The electrode porosity – the ratio of empty space to the whole volume of the electrode – is a metric widely used to characterize the ability of a particular electrode to provide gas transport. It is …