Abstract
The synthesis of silicoaluminophosphate SAPO-37 with the faujasite structure was studied. The present work investigated the influence of several experiment parameters, such as using different silicon sources, aluminum sources, templates, Si/Al ratio in reactant gels, hydrothermal time, and cation effect, on the formation of SAPO-37. It was found that the presence of silica is critical for the formation of SAPO-37. Other structure phases, mainly AlPO4-5 and others, and no SAPO-37 phase, formed in the case of no silica in the starting gel even if SAPO-37 seeding, variation of hydrothermal time, change of P2O5/Al2O3 ratio, and pH adjustment of synthesis gel were taken. SAPO-37 can be synthesized only in the weak base range of pH=8~9. There was no ion effect in the synthesis, such as NH4+ and Na+. The thermal stability of SAPO-37 lowered with the presence of TPA+ in supercage. The release of steam during calcinations led the collapse of SAPO-37 structure. The properties of SAPO-37 were characterized.