LOCATION OF SMALL IRIDIUM AND PLATINUM CLUSTERS IN FAUJASITES

The locations of platinum and iridium clusters with sizes of approxima tely 1 nm grown inside crystals of zeolite X have been determined by h igh-resolution electron microscopy. The metal clusters are located fre quently in positions which do not coincide with the supercage location s. Thus metal clusters which could be accommodated in the supercages o f the globally intact zeolite lattice seem to be often situated at lat tice defects rather than in intact supercages.