Crystalline galloaluminosilicates, steam-modified crystalline galloaluminosilicates, their preparation and their use as catalysts and catalyst supports

摘要

The invention relates to crystalline galloaluminosilicates having an X-ray diffraction pattern substantially the same as that of an MFI-zeolite and a composition in terms of mole ratios of oxides as follows: 0.9+/-0.2 M2/nO.Al2O3. a Ga2O3. b SiO2.zH2O wherein M is a cation, n is the valence of the cation, a has a value between 0.0001 and 2, b has a value of at least 12 and z has a value of from 0 to 40. Ion-exchanged forms, calcined forms and steam-treated forms of the crystalline galloaluminosilicates are also described. Such materials can be used as catalysts and catalyst supports. The steam-treated form is particularly useful as a catalyst for the production of aromatic hydrocarbons from C2 to C12 hydrocarbon feedstocks.