The present invention also relates to a method for preparing metalloaluminophosphate (MeAPO)
molecular sieve said method comprising : a) forming a reaction mixture containing a texture influencing agent (TIA), an organic templating agent (TEMP), at least a reactive inorganic source of MeO2 insoluble in the TIA, reactive sources of Al2O 3 and P2O5, b) crystallizing the above reaction mixture thus formed until crystals of the metalloaluminophosphate are formed, c) recovering a
solid reaction product, d) washing it with water to remove the TIA and e) calcinating it to remove the organic template.In a usual embodiment said reaction mixture has a composition expressed in terms of
molar oxide ratios of: TEMP / Al2O3=0.3-5, more desirable 0.5-2 MeO2 / Al2O3= 0.005-2.0, more desirable 0.022-0.8 P2O5 / Al2O3=0.5-2, more desirable 0.8-1.2 TIA / Al2O3=3-30, more desirable 6-20. In a usual embodiment the metalloaluminophosphate (MeAPO) molecular sieves made with the above method have a lamellar
crystal morphology having an empirical
chemical composition on an
anhydrous basis, after synthesis and
calcination, expressed by the formula HxMeyAlzPkO2 wherein, y+z+k=1, x<=y, y has a value
ranging from 0.0008 to 0.4 and more desirable from 0.005 to 0.18, z has a value
ranging from 0.25 to 0.67 and more desirable from 0.38 to 0.55, k has a value
ranging from 0.2 to 0.67 and more desirable from 0.36 to 0.54, said
molecular sieve having predominantly a plate
crystal morphology. In an advantageous embodiment the MeAPO made by the method of the invention have essentially a structure CHA or AEI or a mixture thereof. Preferably they have essentially the structure SAPO 18 or SAPO 34 or a mixture thereof. The present invention also relates to catalysts consisting of the above MeAPO molecular sieves madeby the method of the invention or comprising the above MeAPO molecular sieves made by the method of the invention.