1. A method for evaluating the spatial distribution of an ionomer in a membrane electrode assembly (MEA), wherein the MEA includes electrodes that have an ionomer, said method comprising: embedding the MEA in a support material; slicing thin sections of the MEA; exposing the MEA sections to a staining material, wherein the staining material is titanium tetrachloride, that stains the support material in the MEA, but does not stain the ionomer, including the electrode ionomer; and viewing the MEA sections to identify the non-stained ionomer regions in the MEA sections.