Résumé
Even though only seldom used in the characterisation of materials of interest in heterogeneous catalysis, Au-197 Mossbauer spectroscopy can yield unique information on the state of gold on going from the molecular precursors and its adsorption on the surface of the support to the final catalyst. In order to emphasise the possibilities of this technique, the main results obtained in the application of the Au-197 Mossbauer technique in the characterisation of supported gold catalysts are shortly reviewed. In the end, the particular case of bimetallic Pt-Ir/SiO2 catalysts, which could be studied at the same time by both Au-197 and Ir-193 Mossbauer spectroscopy, is presented.