title: Nano-magnetic particles as multifunctional microreactor for deep desulfurization.
abstract: Oxidation of dibenzothiophene with hydrogen peroxide using a recyclable amphiphilic catalyst has been studied. The catalyst was synthesized by surfacely covering magnetic silica nanospheres (MSN) with the complexes between 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (AEM) and phosphotungstic acid (PTA). The morphology and components of the composite material were characterized by TEM, EDX, XPS, FT-IR, and VSM, respectively. The effects of several factors on desulfurization reactivity were systematically investigated. The results showed that the composite nanospheres have core/shell structure with the properties of amphiphilicity and superparamagnetism. The composite nanospheres have high catalytic activity in the oxidation of dibenzothiophene to corresponding sulfones by hydrogen peroxide under mild reaction conditions. The sulfur level could be lowered from 487 ppm to less than 0.8 ppm under optimal conditions. Additionally, the amphiphilic catalyst and the oxidized product could be simultaneously separated from medium by external magnetism, and the recovered composite material could be recycled for three times with almost constant activity.
authors.affiliation: Engineering Research Center of Historical and Cultural Heritage Protection, Ministry of Education, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710062, China.
authors.forename: Xinai
authors.initials: X
authors.lastname: Cui
authors.forename: Dongdong
authors.initials: D
authors.lastname: Yao
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.forename: Juxiang
authors.initials: J
authors.lastname: Yang
authors.forename: Daodao
authors.initials: D
authors.lastname: Hu
mesh_terms: D002384:Catalysis; D006861:Hydrogen Peroxide / Q000737:chemistry; D008280:Magnetics; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D054118:Nanospheres / Q000737:chemistry* / Q000648:ultrastructure; D017646:Organosilicon Compounds / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D059027:Recycling; D012822:Silicon Dioxide / Q000737:chemistry*; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013455:Sulfur / Q000737:chemistry*; D013818:Thermogravimetry; D013876:Thiophenes / Q000737:chemistry
chemical_list: D017646:Organosilicon Compounds; D016877:Oxidants; D000644:Quaternary Ammonium Compounds; D013876:Thiophenes; C018408:3-(trimethoxysilyl)propyldimethyloctadecylammonium; D013455:Sulfur; D012822:Silicon Dioxide; D006861:Hydrogen Peroxide; C016366:dibenzothiophene