Synthesis of SAPO-35 in non-aqueous gels

Abstract

The molecular sieve SAPO-35 has been synthesized in a non-aqueous medium for the first time using a new template, hexamethyleneimine. It has been characterized by XRD, SEM, TG–DTA, MAS NMR, FTIR and adsorption techniques. The study indicates that Si replaces mainly the P atoms in the AlPO ₄ -35 framework giving rise to three different Brønsted acid bridging hydroxy groups, with IR absorptions at 3580, 3604 and 3631 cm ⁻¹ . The three bands are attributed to Si incorporation in different tetrahedral positions in double six-membered rings and single six-membered rings.