A Novel Magnetic Solid Acid for Specially Cleaving the C-O Bridged Bond in Dibenzyl Ether

A novel magnetic solid acid was prepared by immobilizing trifluoromethanesulfonic acid (TFMSA) and AlCl3 on a magnetic support (i. e., Fe3O4 coated by SiO2). Dibenzyl ether (DBE) which contains C-O bridged-bond was used as a coal model compound to evaluate the activity of the catalyst for cleaving C-alk-O bonds in coal. The prepared magnetic solid acid was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectrometer, scanning electron microscopy and energy dispersive spectrometer, and NH3-temperature-programmed desorption. The results show that the prepared catalyst possesses nanometer size, core-shell structure and strong acidity. The C-alk-O bond in DBE can be cleaved at a temperature of as low as 413 K over the catalyst AlCl3-TFMSA/Fe3O4/SiO2. The attack of H+ that generated from the magnetic solid acid and/or via hydrogen heterolysis on oxygen atom of DBE could be a crucial step for DBE hydrocracking over the magnetic solid acid.