Interlayer expansion of the layered zeolite precursor COK-5 with Sn(acac)2Cl2

In the interlayer expansion of the layered zeolite precursor COK-5, a Sn, salt, bis(2,4-pentanedionate)-dichlorotin [Sn(acac)2Cl2], instead of a silylating agent was used to link the layers at 180 °C. The obtained material, which is designed as Sn-COE-5, shows a shift of the first XRD reflection, which is very similar to that of COK-5 interlayer expanded with dichlorodimethylsilane (DCDMS), indicating an increase in interlayer distance. X-ray diffraction (XRD), N2 sorption isotherms, inductively coupled plasma (ICP), and X-ray photoelectron spectroscopy (XPS) support the incorporation of isolated Sn sites in the sample. In the conversion of glucose to levulinic acid, Sn-COE-5 exhibits much higher activity than COK-5, which is due to the presence of Lewis acidic sites in the Sn-COE-5.

Graphical abstract A new zeolite containing tin species (Sn-COE-5) is successfully synthesized from an interlayer expansion reaction of layered COK-5 precursor with a tin salt of Sn(acac)2Cl2, which is catalytically active for the conversion of glucose to levulinic acid.Figure optionsDownload full-size imageDownload as PowerPoint slide