Novel mesoporous silicotinphosphate molecular sieve with high anion exchange capacity

Abstract

New mesoporous silicotinphosphate materials with different Si:Sn:P mole ratios have been synthesized under hydrothermal condition using the self-assembly of cationic surfactant under mild acid pHs and characterized by elemental analysis, XRD, TEM, SEM-EDS, N 2 sorption, FT IR, and UV–vis diffuse reflectance measurements and ion-exchange studies. XRD and TEM results suggested a wormhole-like disordered framework in this material. N 2 adsorption studies revealed that the pore diameters of different samples were 1.7–2.2 nm. FT IR and UV–vis spectroscopic studies suggested the presence of Sn–O–P, Sn–O–Si bonds and tetrahedral coordination of Sn(IV) in these novel mesoporous materials. These novel silicotinphosphate materials showed good anion-exchange capacities (2.56–0.27 mmol g −1, which correspond well with their respective Si:Sn:P mole ratios in the solid products) and catalytic activity in the liquid phase epoxidation of styrene using dilute H 2O 2 as oxidant.