title: Isomerization of n-hexane over silica-supported heteropoly acids promoted by the reduced Ce-Ni oxides.
abstract: The structure and catalytic properties of silica-supported heteropoly acids promoted by the reduced Ce-Ni oxides are first studied by using chemical analysis XRD, FT-Raman, XPS, EPR, TG, surface area measurements, and microreactor test. It is found that silica-supported heteropoly acids have isomerization activity, but are very easy to deactivate by coke deposition. With the promotion of the reduced Ce-Ni oxides, however, the better activity and the higher selectivity to isomers could be obtained, suggesting that the reduced Ce-Ni oxides really have hydrogenating/dehydrogenating functions. Moreover, it is found that the presence of the reduced Ce-Ni oxides is not only beneficial for eliminating the coke deposition, but also effective for maintaining the structure of silica-supported heteropoly acids during reaction. The effect of the composition of the mechanical mixtures of silica-supported heteropoly acids and the Ce-Ni oxides on the catalytic properties has been explored.
authors.affiliation: Laboratoire de Catalyse Hétérogène et Homogène, UPRESA 8010, Bâtiment C3, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq Cedex, 59655, France.
authors.forename: Wenxing
authors.initials: W
authors.lastname: Kuang
authors.forename: Alain
authors.initials: A
authors.lastname: Rives
authors.forename: Bouchta Ouled
authors.initials: BO
authors.lastname: Ben Tayeb
authors.forename: Michel
authors.initials: M
authors.lastname: Fournier
authors.forename: Robert
authors.initials: R
authors.lastname: Hubaut
mesh_terms: D000143:Acids / Q000737:chemistry*; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D006586:Hexanes / Q000737:chemistry*; D007536:Isomerism; D009532:Nickel / Q000737:chemistry*; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods; D013499:Surface Properties; D013696:Temperature
chemical_list: D000143:Acids; D006586:Hexanes; C026385:n-hexane; D002563:Cerium; C030583:ceric oxide; D012822:Silicon Dioxide; D009532:Nickel; C028007:nickel monoxide