Microprobe applications for the characterization of catalyst systems

The characterization of heterogeneous catalysts by ion beam and microprobe methods is briefly reviewed. Typical properties regarding composition and s tructure of supported catalysts are considered. These are often favorable f or ion beam analysis (heavy adsorbate on light substrate) and have morpholo gical structures in the regime of microprobe resolution (mu m). Ion beam me thods have promising potential (quantification, depth information) for cata lyst characterization but they are not yet extensively used in this field. Microprobe analysis has to be compared with other spatially resolving metho ds, particularly electron microscopy. The advantage of ion microprobes lies in the possibility to obtain mass sensitive lateral information. As a spec ial topic the investigation of material spreading as a case of solid-solid wetting is discussed, which has been investigated by low and high energy io n scattering, laser Raman microscopy (LRM) and recently with scanning photo electron microscopy (SPEM). Spreading opens a possibility for an interestin g new way to catalyst preparation. (C) 1999 Elsevier Science B.V. All right s reserved.