title: Mechanism of catalytic ozonation in Fe ₂O₃/Al ₂O₃@SBA-15 aqueous suspension for destruction of ibuprofen.
abstract: Fe2O3 and/or Al2O3 were supported on mesoporous SBA-15 by wet impregnation and calcinations with AlCl3 and FeCl3 as the metal precursor and were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectra (FTIR) of adsorbed pyridine. Fe2O3/Al2O3@SBA-15 was found to be highly effective for the mineralization of ibuprofen aqueous solution with ozone. The characterization studies showed that Al-O-Si was formed by the substitution of Al(3+) for the hydrogen of surface Si-OH groups, not only resulting in high dispersion of Al2O3 and Fe2O3 on SBA-15, but also inducing the greatest amount of surface Lewis acid sites. By studies of in situ attenuated total reflection FTIR (ATR-FTIR), in situ Raman, and electron spin resonance (ESR) spectra, the chemisorbed ozone was decomposed into surface atomic oxygen species at the Lewis acid sites of Al(3+) while it was converted into surface adsorbed (•)OHads and O2(•-) radicals at the Lewis acid sites of Fe(3+). The combination of both Lewis acid sites of iron and aluminum onto Fe2O3/Al2O3@SBA-15 enhanced the formation of (•)OHads and O2(•-) radicals, leading to highest reactivity. Mechanisms of catalytic ozonation were proposed for the tested catalysts on the basis of all the experimental information.
authors.affiliation: Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors.forename: Jishuai
authors.initials: J
authors.lastname: Bing
authors.forename: Chun
authors.initials: C
authors.lastname: Hu
authors.forename: Yulun
authors.initials: Y
authors.lastname: Nie
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Jiuhui
authors.initials: J
authors.lastname: Qu
mesh_terms: D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry; D002384:Catalysis; D004578:Electron Spin Resonance Spectroscopy; D005290:Ferric Compounds / Q000737:chemistry; D007052:Ibuprofen / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010126:Ozone / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D012822:Silicon Dioxide / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013535:Suspensions; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D005290:Ferric Compounds; C509969:SBA-15; D013535:Suspensions; D014867:Water; D010126:Ozone; D012822:Silicon Dioxide; D000537:Aluminum Oxide; D010100:Oxygen; D007052:Ibuprofen