A practical method to characterize proton exchange membrane fuel cell catalyst layer topography: Application to two coating techniques and two carbon supports

•Proton Exchange Membrane Fuel Cell coatings prepared by film casting and spraying.•The topography was characterized by profilometry and 3D laser scanning microscopy.•Methods were developed for accurate 3D data processing.•A comparison has been made between these two 3D profile characterization techniques.•The complementarity of these two techniques was demonstrated.