title: Post-synthesis, characterization and catalytic properties of fluorine-planted MWW-type titanosilicate.
abstract: F-Ti-MWW was post-synthesized by implanting fluorine species into a Ti-MWW framework through an acid treatment process in the presence of ammonium fluoride. The effects of NH4F addition amount, acid treatment temperature and precursor Ti content were investigated on the incorporation of F species, the zeolite structure and the coordination sites of Ti. Fluorine-implanting improved the surface hydrophobicity of the zeolite and altered the electropositivity nearby the tetrahedral Ti sites through forming the SiO3/2F and SiO4/2F(-) units. The negative effect of SiO4/2F(-) units in F-Ti-MWW was eliminated selectively by convenient anion-exchange with various alkali chlorides. F-Ti-MWW containing the SiO3/2F units possessed better catalytic activity and reusability, and a longer catalyst lifetime than conventional Ti-MWW.
authors: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, Shanghai, China.
authors: Xiangqing
authors: X
authors: Fang
authors: Qiang
authors: Q
authors: Wang
authors: Anmin
authors: A
authors: Zheng
authors: Yueming
authors: Y
authors: Liu
authors: Longfei
authors: L
authors: Lin
authors: Haihong
authors: H
authors: Wu
authors: Feng
authors: F
authors: Deng
authors: Mingyuan
authors: M
authors: He
authors: Peng
authors: P
authors: Wu
mesh_terms: D064751:Ammonium Compounds; D002384:Catalysis; D005459:Fluorides / Q000737:chemistry*; D015394:Molecular Structure; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D064751:Ammonium Compounds; D000644:Quaternary Ammonium Compounds; D017640:Silicates; C024822:ammonium fluoride; D014025:Titanium; D005459:Fluorides