This method is for determining the extent of platinumagglomeration in reforming catalysts, i.e., the fraction of theplatinum in the sample that has agglomerated into crystalliteslarger than 3.5 nm, using X-ray diffraction. These materialsgenerally contain between 0.2 to 0.4 mass-% platinum onpredominantly gamma-alumina support. This method is also forqualitatively determining the alumina types present in thesample.

Catalyst samples may be either fresh, spent or regenerated, astypical levels of carbon, sulfur and moisture associated with thesesamples do not interfere. Reforming catalysts containing less than2% zeolitic materials may also be analyzed. Samples where theplatinum has formed an alloy with other metals such as tin,rhodium, rhenium or iron cannot be analyzed by this method.