Advances in the Application of Mossbauer Spectroscopy with Less-Common Isotopes for the Characterisation of Bimetallic Supported Nanoparticles: ~(193)Ir Mossbauer Spectroscopy

摘要

A detailed picture of the state of iridium in materials of interest in heterogeneous catalysis can be obtained by ~(193)Ir Mossbauer spectroscopy. This technique can yield unique information on the chemical state of iridium on going from the molecular precursors and its adsorption on the surface of the support. It allows the estimation of the composition of the Ir-containing alloys that are possibly formed during the activation treatments of supported bimetallic systems. In order to point out the possibilities of this technique, the main results obtained in the application of ~(193)Ir Mossbauer spectroscopy to two Ir-containing bimetallic supported nanoparticles, i.e., the Pt-Ir on amorphous silica and the Fe-Ir on magnesia, will be presented and discussed relative to their synthesis and the influence of the preparation methods.