Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-IV-7MESOPOROUS ANODES BASED ON YSZ DOPED WITHTiO 2 OR CeO 2 FOR DIRECT OXIDATION OF HYDROCARBONSIN ELECTROCATALYTIC MEMBRANE REACTORV. Pârvulescu 1 , S. Somacescu 1 , P. Osiceanu 1 , A. Cojocaru 2 , D-I. Vaireanu 2 and B.L. Su 31 Institute of Physical Chemistry, Spl. Independentei 202, Bucharest, RomâniaE-mail: vpirvulescu@chimfiz.icf.ro2 University Politehnica of Bucharest, Faculty of applied Chemistry and Materials Science,1-7 Polizu St., Bucharest3 University of Namur (FUNDP), Laboratoire de Chimie des Matériaux Inorganiques,61 rue de Bruxelles, B-5000 Namur, BelgiumIntroductionFuel cells with solid oxide (SOFCs) show the most promise for being able to directlyutilize hydrocarbon fuels [1]. Developments of intermediate-temperature solid oxide fuel cellsrequire optimization of anode compositions and microstructure. Incorporation of titania orceria was proved to enhance the performance of conventional anode cermets, consisting ofmetallic Ni and yttria stabilized zirconia (YSZ). The present study is centered on the synthesisof mesoporous Ni and 8 mol% yttria-stabilized zirconia doped with titania or ceria andutilization of these materials in direct oxidation of hydrocarbons in electrocatalytic membranereactor. The application of membrane reactors to the hydrocarbon oxidation has attractedconsiderable attention in the recent years [2,3].ExperimentalMesoporous x%TiO 2 (CeO 2 ) - ZrO 2 – 8%Y 2 O 3 powders with x = 5, 10, 15, 20 and 30molar content were synthesized by hydrothermal treatment using cetyltrimetyl-ammoniumbromide as surfactant, zirconium oxychloride - ZrOCl 2 , Y(NO 3 ) 3 , titanium propoxide asinorganic precursors and urea as the hydrolyzing agent. The molar ratio used was thefollowing: oxide/surfactant/urea = 1: 0, 36: 7. The mixture was loaded into Teflon link steelautoclave and heated 3 days at 100 °C. All the products obtained were filtered, washed anddried at 100 °C and calcinated in a flow of N 2 followed by a flow of air at 550 °C. Ni wassupported by impregnation from aqueous Ni (NO 3 ) 2 solution. The obtained materials werecharacterized by X-ray diffraction, SEM and TEM microscopy, IR, UV-Vis, X-rayPhotoelectron and electrochemical impedance (EI) spectroscopy, N 2 adsorption-desorption.Two electrode and three electrode cell configurations were used in conjunction with EIS, inthe range of 100 KHz to 10m Hz, to determine the ionic resistivity and its dependence on theTiO 2 and CeO 2 concentration. The electrochemical reactor was constructed from YSZ disc of408