X-RAY-ABSORPTION AND X-RAY PHOTOELECTRON-SPECTROSCOPY OF A RHODIUM COLLOID

Transition metal colloids are potential precursors of heterogeneous ca talysts with application to selective chemical reactions. Sample prepa ration techniques are described. Experimental details are given of the characterization of these often air-sensitive particles by X-ray phot oelectron and X-ray absorption spectroscopy. First results obtained wi th both techniques for a Rh-colloid show that the metal is mainly pres ent in the zerovalent chemical state. But the spectra indicate further chemical states of Rh which can be assigned to the outermost metal at oms of the colloid interacting with organic ligands or to the educt Rh -halides.