AVS 56th International Symposium & Exhibition
    Applied Surface Science Wednesday Sessions
       Session AS-WeM

Paper AS-WeM10
XPS Imaging Techniques for the Chemical Characterization of Fuel Cell Membrane Electrode Assemblies

Wednesday, November 11, 2009, 11:00 am, Room C2

Session: Electron Spectroscopies
Presenter: A.E. Wright, Thermo Fisher Scientific, UK
Authors: A.E. Wright, Thermo Fisher Scientific, UK
T.S. Nunney, Thermo Fisher Scientific, UK
R.G. White, Thermo Fisher Scientific, UK
K.S. Reeves, Oak Ridge National Laboratory
K.L. More, Oak Ridge National Laboratory
H.M. Meyer III, Oak Ridge National Laboratory
Correspondent: Click to Email
Fuel cell technology is reliant on the successful development of membrane electrode assemblies (MEA), which consist of a proton exchange membrane (PEM) sandwiched between catalyst-containing anode and cathode layers. X-ray photoelectron spectroscopy (XPS) with its high surface sensitivity and chemical state sensitivity is an ideal technique for characterizing fuel cell MEA chemical composition. Typically MEA membranes are in the range of 20-50µm thick, ruling out practical usage of conventional Ar ion or other profiling methods to obtain chemical composition profiles. To overcome these sample analysis constraints the MEA samples were prepared using an ultra low-angle microtomy (ULAM) technique. With the ULAM sectioning technique it is possible to extend a ~25 µm thick membrane to present an analysis area of over 400µm. Extending the analysis area of the MEA cross-section improves the opportunity to extract chemical state imaging information using a non-microscopy based technique such as XPS. Minimization of X-ray induced damage, preserving of chemical state information, is considered a significant experimental consideration for XPS polymer analysis. For this reason, rapid acquisition modes are preferred. This presentation will focus on the practicalities of rapid of XPS image acquisition methods and automated data review and processing techniques for the study of MEA structures

Research supported by the U.S. Dept. of Energy, Office of Energy Efficiency and Renewable Energy, Hydrogen, Fuel Cell, and Infrastructure Technologies Program. Research at the ORNL SHaRE User Facility was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Dept. of Energy.