Tin incorporated periodic mesoporous organosilicas (Sn–PMOs): Synthesis, characterization, and catalytic activity in the epoxidation reaction of olefins

Tin incorporated mesoporous organosilicas (Sn–PMO) having uniform hexagonal arrangements were prepared using alkyl trimethylammonium bromide surfactants under basic reaction conditions. Characterization techniques revealed that the structural ordering, morphology, and the percentage of tin incorporation depend critically on the hydrophobic chain length of surfactants. The Sn–PMO samples are thermally stable up to 500 °C under air atmosphere and were hydrothermally stable up to 100 h in boiling water. The organotinsilicates showed excellent catalytic activity and reusability in the epoxidation of norbornene and cis-cyclooctene than an Sn–MCM-41 due to organic groups in the frame wall positions and the better accessibility of reactants to the active sites.

Graphical AbstractTin-containing –CH2–CH2–silica hybrid mesoporous organosilicas (Sn–PMO) having uniform hexagonal arrangement were prepared under basic conditions using alkyl trimethyl ammonium surfactants of different chain lengths. The samples evaluated in the epoxidation reaction of norbornene and cis-cyclooctene exhibited high activity than a Sn–MCM-41 material.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch Highlights► New Sn-PMO materials with ethane groups in the frame wall positions were synthesized for the first time using cationic surfactants of different chain lengths. ► Cationic surfactants having C18- chain length showed better mesostructural ordering and percentage of tin incorporation than short alkyl chain C16- and C14- surfactants. ► Sn-PMO catalysts showed high activity, and stability than conventional Sn-MCM-41 samples, due to its inherent hydrophobic nature.