title: Sponge phase producing porous CeO2 for catalytic oxidation of CO.
abstract: The aggregation behavior of mixtures of the alkaline amino acid L-Arginine (L-Arg) and bis(2-ethylhexyl)phosphoric acid (DEHPA) in water was studied in detail. At a fixed L-Arg concentration, a phase sequence of micellar phase (L1 phase), vesicle phase (Lαv phase), planar lamellar phase (Lαl phase), and sponge phase (L3 phase) was obtained with increasing DEHPA concentration due to changes in the packing parameter. The phase transition of the lamellar structures was determined by freeze-fracture TEM and (2)H NMR spectroscopy. Rheological measurements reflected the phase transition through significant variations of both the elastic modulus and the viscous modulus. Porous CeO2 materials were produced by utilizing the L3 phase as template, and the porous CeO2 exhibited excellent catalytic oxidation activity toward CO due to its high surface area, which provides more active sites for CO conversion.
authors.affiliation: Key Laboratory of Colloid and Interface Chemistry & Key Laboratory of Special Aggregated Materials, Shandong University, Ministry of Education, Jinan 250100 (P. R. China), Fax: (+86) 531-8856-4750.
authors.forename: Shasha
authors.initials: S
authors.lastname: Song
authors.forename: Haiqiao
authors.initials: H
authors.lastname: Wang
authors.forename: Aixin
authors.initials: A
authors.lastname: Song
authors.forename: Shuli
authors.initials: S
authors.lastname: Dong
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Hao
mesh_terms: D001120:Arginine / Q000737:chemistry; D002248:Carbon Monoxide / Q000737:chemistry*; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D008823:Micelles; D010084:Oxidation-Reduction; D044367:Phase Transition; D010756:Phosphoric Acids / Q000737:chemistry; D016062:Porosity
chemical_list: D008823:Micelles; D010756:Phosphoric Acids; D002563:Cerium; C030583:ceric oxide; D002248:Carbon Monoxide; D001120:Arginine
keywords: micelles; oxidation; sponge phases; template synthesis; vesicles