Zeolite framework functionalisation by tuneable incorporation of various metals into the IPC-2 zeolite
Abstrakt
The incorporation of various metals into the zeolite framework creates opportunities for novel applications, especially in catalysis. The recently developed assembly-disassembly-organisation-reassembly (ADOR) strategy was used to prepare zeolites with IPC-2 (OKO) topology.
The layered zeolite precursor (IPC-1P) was modified by incorporating various metals (Al, Zn, Sn, Zr, V, Fe, Hf, and Ti) using a stabilisation process. The resulting materials were characterised by X-ray powder diffraction (XRD), Ar adsorption, scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), and diffuse reflectance UV-Vis spectroscopy (DR-UV-Vis).
The acidity of Al-containing IPC-2 materials was assessed by acetonitrile and pyridine sorption followed by FT-IR spectroscopy, showing overall concentrations of acid sites of 0.863 mmol g(-1) (acetonitrile) and 0.413 mmol g(-1) (pyridine). Titanium containing IPC-2 was examined by selective oxidation of methylphenyl sulfide (MPS) to the corresponding sulfoxide (MPSO).
Ti-IPC-2 provided a higher conversion than TS-1 after 60 min (30% and 18% respectively) and showed higher selectivity towards MPSO (77% and 63% respectively). Sn-IPC-2 was tested by Baeyer-Villiger oxidation of norcamphor with aqueous hydrogen peroxide, showing a 3.8% norcamphor conversion and a 1.3% yield of the desired lactone (after 8 h reaction).
Therefore, the results reported herein clearly show the successful incorporation of metals into the IPC-2 zeolite framework.