Controllable Synthesis And Application Of AlPO₄-5 Molecular Sieves

In this paper, A1PO4-5 molecular sieve was selected as the main research object from the perspective of the synthesis. Firstly, the A1PO4-5 crystals with regular morphology, high crystallinity and different aspect ratio were successfully synthesized by adjusting the composition of the synthesis gel. Luminescence dye was further loaded inside of the AIPO4-5 crystals channels and proved by the luminescence spectra analysis results. Secondly, highly c-oriented AIPO4-5 membrane was fabricated by using the Langmuir-Blodgett method. Both stainless steel and porous alumina were selected as substrates. Single gas permeation test was further tested for membranes. Finally, ZSM-5/AJPO4-5 composite catalyst with core-shell structure was prepared by growth the AIPO4-5 on the surface of ZSM-5. The catalytic properly of this composite catalyst was investigated by the MTO reaction. The detail of this paper is described as following.1. Both general hydrothermal synthesis method and microwave crystallization method were employed for the synthesis A1PO4-5 crystals by changing the molar composition of the synthesis mixture with a molar ratio of IAI2O3:1.3P2O5:mTEA:nH2O:yHF. The AlPO4-5 crystals with regular morphology, high crystallinity and different aspect ratio were successfully synthesized. With the synthetic AIPO4-5 molecular sieve as the main body, guest molecules Rhodamine B was assembled by solvent diffusion method and situ crystallization legal package. Luminescence spectra analysis results proved that the Rhodamine B was assembled inside the AIPO4-5 pores successfully.2. Highly c-oriented AIPO4-5 films and membranes were prepared on both stainless steel and porous alumina substrates by secondary growth of the compact seeds layer fabricated by Langmuir-Blodgett technique. The morphology and orientation of AIPO4-5 membrane can be adjusted by changing the secondary hydrothermal growth conditions and by adding a small amount of HF. Single gas permeation test proved that the oriented A1PO4-5 membranes were defect free with highly separation ratio for H2 and CO2.3. The core/shell structure of ZSM-5/A1PO4-5 composite zeolite was synthesized by secondary growth AIPO4-5 crystals on the surface of ZSM-5 core, and their catalytic properties for MTO were investigated. The catalytic results indicated that the composite zeolite increased the yield of olefins compared with pure ZSM-5.