Abstract: The LTA type aluminophosphate molecular sieve (AlPO4-42) was ionothermally synthesized by introducing organic amine into the 1-butyl-3-methylimidazolium bromide ([bmim]Br) ionic liquid. The as-synthesized products were characterized and the crystallization ki-netics was investigated. Thermal gravimetric analysis, nuclear magnetic resonance spectroscopy, and infrared spectroscopy demonstrated that the organic amine and the cation of the ionic liquid filled in the channels of the molecular sieve together. The introduced amine acted as the synergetic templates in a certain aggregated state according to the result of photoluminescence emission spectroscopy. The final products varied with the crystallization time, and the kinetic pathway was influenced by the amine concentration, which decreased with the growth of the crystal product during the crystallization. The inorganic materials reassembled around these aggregated templates when they exist in a high concentration to form sod or lta cages, resulting in the crystallization of cubic LTA framework.

Key words: ionothermal synthesis, aluminophosphate molecular sieve, organic amine, co-template, LTA type structure