TEM-TOMOGRAPHY OF FAU-ZEOLITE CRYSTALS CONTAINING PT-CLUSTERS

A method for preparing ultrathin sections (similar to 20 nm) of inorga nic solids has been developed using ultramicrotomy of resin-embedded c rystal fragments. Undamaged crystals, oriented along a crystallographi c direction, could be imaged with transmission electron microscopy (TE M) at a resolution better than 0.5 nm. The true internal structure of the crystals could be investigated by imaging the second in a series o f at least three consecutive ultrathin sections. Such TEM-tomography p roved that Pt-ion exchanged FAU zeolite crystals, after reduction and oxidation, are occupied internally and randomly of large platinum clus ters mainly in the {111}-twin planes. TEM-tomography could be useful i n man made nanostructures like semiconductors, epitaxial thin films, h ard metal coatings, ceramics, catalysts, and biomaterials.