Silicoaluminophosphate molecular sieve SAPO-41: Synthesis, characterization and alkylation of toluene with alcohol

Abstract

A silicoaluminophosphate molecular sieve SAPO-41 has been synthesized and characterized by XRD, 27Al, 31P, 29Si MASNMR, FT-IR spectroscopy, TG/DTA, scanning electron microscopy and chemical analysis. Catalytic activity of these materials in the alkylation of toluene with alcohol has been studied. SEM reveals the morphology (spherical) and particle size (10 mm) of the sample. Hydroxyl region infrared spectroscopy reveals the presence of peaks at 3625, 3650, 3670 and 3730 cm1, which are due to the presence of silanol, P-OH and Si-OH groups. 27Al and 31P MASNMR results show the presence of tetrahedrally coordinated aluminium and phosphorous atoms.However, 29Si MASNMR shows peaks at 92, 95, 100 and 107 ppm due to silicon surrounded by four AlO4 tetrahedra and to silicon surrounded by 3AlO4, 2AlO4 and 1AlO4 respectively. In the case of toluene, alkylation with alcohol para isomer is predominant over the ortho and meta isomers.