LAUSR

Abstract AlPO4-5 has been synthesized in nonaqueous (ethylene glycol) system using hexamethyleneimine (HMI) as structure directing agent. Using the reactive gel composition: 1.0 Al2O3: 1.8 P2O5: 4.5 HMI: 45.0 EG, pure and high crystalline AlPO4-5 could be obtained at 200 °C for 15 d. IR, Raman, 27Al NMR and 31P NMR experiments were used to identify the P–O–Al bonded species in the intermediate phases. P–O–Al unites exist in the product when heating for 1 d, while the aluminophosphate framework is formed after the reaction time increasing for 3 d. Pure AlPO4-5 is produced at 10 d and the solid has the highest crystalline after heating for 15 d 13C NMR was used to monitor the development of HMI during the crystallization process. TG/DTA experiment shows that the thermal stability of the AlPO4-5 up to 1000 °C. In addition, the influences of temperature, alkalinity and amount of HMI in the starting gels were also studied.