Synthesis of ionic liquid-functionalized mesoporous SBA-15 containing copper porphyrin for oxidation of trimethylphenol

In this study, immobilization of anionic copper metalloporphyrin (CuTSPP) on ionic liquid-functionalized mesoporous SBA-15 (ImIL@SBA) with different CuTSPP loading (5, 10 and 25 μmol) was achieved by the post-synthesis ion-exchange method, affording the CuTSPP-ImIL@SBA. The prepared catalysts have been characterized by a variety of physicochemical techniques including N2 adsorption-desorption, diffuse reflectance ultraviolet-visible (DR UV-Vis) spectroscopy, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis. It is found that the decreased BET surface area with increasing amount of CuTSPP loading up to 25 µmol was ascribed to the filling of pores of ImIL@SBA by the CuTSPP complex. Moreover, DR UV-Vis spectra of CuTSPP-ImIL@SBA showed the Soret band of CuTSPP complex is often in the range of 400-500 nm, while the Q bands fall between 500-700 nm. The catalytic activity of the prepared CuTSPP-ImIL@SBA catalysts was tested in the one-step oxidation of 2,3,6-trimethylphenol (TMP), using tert-butyl hydroperoxide (TBHP) as oxidant. The only product obtained which is 2,3,5-trimethylbenzoquinone (TMBQ) were analyzed using GC-FID and GC-MS.