Fabrication of SAPO-34 Crystals with Different Morphologies by Microwave Heating

The crystal size and shape of the silicoaluminophosphate molecular sieve SAPO-34 have been effectively controlled in the reaction system of Al₂O₃–P₂O₅–SiO₂–TEAOH–H₂O under microwave radiations. Nano sheet-like SAPO-34 crystals are obtained when using colloidal silica as the silica source. When TEOS is used as the source of silica, homogeneous SAPO-34 crystals with a particle size of about 100 nm are formed, and the morphology of the crystals changes from uniform nano particles (~100 nm) to microspheres (~1.5 μm) by varying the H₂O/Al₂O₃ molar ratio. To further investigate the morphology control of SAPO-34, the synthetic factors, such as the silica source, water content, crystallization time and aging time have been studied in detail.