title: High Surface Area Ceria for CO Oxidation Prepared from Ceriumt-Butoxide by Combined Sol-Gel and Solvothermal Processing.
abstract: CeO2was synthesized by combined sol-gel and solvothermal processing of gels obtained from acetaldoximate-modified cerium(IV)t-butoxide in the presence of the non-ionic surfactant Pluronic F127. The use of cerium(IV)t-butoxide as precursor contrasts very favorably with the often used ceric ammonium nitrate and results in more reliable and tailorable properties of the final materials. The kind of post-synthesis treatment of the gels and the composition of the precursor mixture proved to be crucial for obtaining high surface area ceria with a high Ce3+proportion. Calcination in air or under nitrogen was compared with solvothermal treatment in ethanol or water and a combination of solvothermal treatment and calcination. The obtained materials are composed of 3.5-5.5 nm ceria nanoparticles. The highest specific surface area of 277 m2/g was obtained after solvothermal treatment, and 180 m2/g when solvothermal treatment was followed by calcination in air to remove residual organic groups. The highest Ce3+proportion was 18 % after solvothermal treatment in ethanol and additional calcination in air. CO oxidation on selected samples indicated that activity scaled with surface area and thus was largest for samples solvothermally treated in ethanol. The reaction rate of the best sample was about 75-times larger than that of commercial ceria.
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authors.affiliation: Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Wien, Austria.
authors.forename: Jingxia
authors.initials: J
authors.lastname: Yang
authors.affiliation: Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Wien, Austria.
authors.forename: Liliana
authors.initials: L
authors.lastname: Lukashuk
authors.affiliation: Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Wien, Austria.
authors.forename: Hao
authors.initials: H
authors.lastname: Li
authors.affiliation: Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Wien, Austria.
authors.forename: Karin
authors.initials: K
authors.lastname: Föttinger
authors.affiliation: Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Wien, Austria.
authors.forename: Günther
authors.initials: G
authors.lastname: Rupprechter
authors.affiliation: Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Wien, Austria.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schubert
keywords: CO oxidation; Ceria; Cerium butoxide; Solvothermal treatment; Sol–gel processing