Synthesis, characterization and catalytic properties of a LEV type silicoaluminophosphate molecular sieve, SAPO-35 from aqueous media using aluminium isopropoxide and hexamethyleneimine template

A small-pore silicoaluminophosphate molecular sieve, SAPO-35 was synthesized using hexamethyleneimine template and aluminium isopropoxide as aluminium source in aqueous media is reported for the first time. Pure, highly crystalline samples were obtained in short period (96 h). The samples crystallize at narrow silicon content (0.3 M SiO2). Fourier transform Infrared spectroscopic studies reveal the presence of three different silanol groups. A comparison with multinuclear solid-state Magic angle spinning nuclear magnetic resonance spectroscopic studies with FT-IR studies shows that these groups are located at Double six member ring, near to D6R and near to single six member ring. Other characterizations and methanol to olefin reaction studies shows that the molecular sieves synthesized by aqueous and non-aqueous media are having comparable properties. It reveals a possible application of this catalyst for industrial process.

Graphical abstractA levyne type silicoaluminophosphate molecular sieve, SAPO-35 is synthesized using aluminium isopropoxide in aqueous media for the first time. The synthesized material was characterized using different physicochemical techniques and its comparison with non-aqueous media samples of same molar ratio and from same aluminium source and template, shows that it is having superior properties.Figure optionsDownload full-size imageDownload as PowerPoint slide