Role of the Aluminophosphate Gel Aging Stage in Controlling the Morphology and Secondary Pore Structure of AlPO4-11 Molecular Sieves

The effect of the aging stage on the chemical and phase composition and pore structure characteristics of aluminophosphate gels synthesized using boehmite and phosphoric acid and the products of the subsequent crystallization of the gels into aluminophosphate AlPO 4 -11 has been studied by XRD, 27 Al and 31 P MAS NMR, SEM, and nitrogen adsorption–desorption. It has been shown that the control of the chemical and phase composition of aluminophosphate gels via varying their aging temperature in a range of 25–120°C makes it possible to synthesize a high phase purity AlPO 4 -11 aluminophosphate and change the morphology and secondary pore structure characteristics of the AlPO 4 -11 crystals without using various growth modifiers.