title: Enhanced catalytic activity of sub-nanometer titania clusters confined inside double-wall carbon nanotubes.
abstract: Sub-nanometer titania clusters have been homogeneously dispersed within double-wall carbon nantubes (DWNTs) with an inner diameter ranging from 1.0 to 1.5 nm. The confined titania exhibits a much higher activity than the titania particles attached on the outside walls of the DWNTs (the outside titania) in the epoxidation of propylene by H(2)O(2). XPS, XANES and Raman spectroscopy data suggest electron transfer from titanium to the inner surfaces of the DWNTs. In contrast, no electron transfer has been observed for the outside titania. We also found that the extent of this confinement-induced electron transfer is temperature dependent. The enhanced activity of the confined titania clusters is likely attributed to their small sizes and the interaction with the DWNT surface. The synthesis method that we developed here can be readily applied to incorporation of other metal/metal oxide nanoparticles into carbon nanotubes.
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, the Chinese Academy of Sciences, Dalian, PR China.
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhang
authors.forename: Xiulian
authors.initials: X
authors.lastname: Pan
authors.forename: Jingyue Jimmy
authors.initials: JJ
authors.lastname: Liu
authors.forename: Weizhong
authors.initials: W
authors.lastname: Qian
authors.forename: Fei
authors.initials: F
authors.lastname: Wei
authors.forename: Yuying
authors.initials: Y
authors.lastname: Huang
authors.forename: Xinhe
authors.initials: X
authors.lastname: Bao
mesh_terms: D002384:Catalysis; D049329:Nanostructures / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D013057:Spectrum Analysis; D014025:Titanium / Q000737:chemistry*
chemical_list: D037742:Nanotubes, Carbon; C009495:titanium dioxide; D014025:Titanium