title: Methane Decomposition and Carbon Growth on Y2O3, Yttria-Stabilized Zirconia, and ZrO2.
abstract: Carbon deposition following thermal methane decomposition under dry and steam reforming conditions has been studied on yttria-stabilized zirconia (YSZ), Y2O3, and ZrO2by a range of different chemical, structural, and spectroscopic characterization techniques, including aberration-corrected electron microscopy, Raman spectroscopy, electric impedance spectroscopy, and volumetric adsorption techniques. Concordantly, all experimental techniques reveal the formation of a conducting layer of disordered nanocrystalline graphite covering the individual grains of the respective pure oxides after treatment in dry methane at temperaturesT≥ 1000 K. In addition, treatment under moist methane conditions causes additional formation of carbon-nanotube-like architectures by partial detachment of the graphite layers. All experiments show that during carbon growth, no substantial reduction of any of the oxides takes place. Our results, therefore, indicate that these pure oxides can act as efficient nonmetallic substrates for methane-induced growth of different carbon species with potentially important implications regarding their use in solid oxide fuel cells. Moreover, by comparing the three oxides, we could elucidate differences in the methane reactivities of the respective SOFC-relevant purely oxidic surfaces under typical SOFC operation conditions without the presence of metallic constituents.
authors.affiliation: Institute of Physical Chemistry, University of Innsbruck , Innrain 52a, A-6020 Innsbruck, Austria.
authors.forename: Michaela
authors.initials: M
authors.lastname: Kogler
authors.affiliation: Institute of Physical Chemistry, University of Innsbruck , Innrain 52a, A-6020 Innsbruck, Austria.
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Köck
authors.affiliation: Institute of Mineralogy and Petrography, University of Innsbruck , Innrain 52f, A-6020 Innsbruck, Austria.
authors.forename: Lukas
authors.initials: L
authors.lastname: Perfler
authors.affiliation: Institute of Physical Chemistry, University of Innsbruck , Innrain 52a, A-6020 Innsbruck, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bielz
authors.affiliation: University Service Centre for Transmission Electron Microscopy (USTEM), Vienna, University of Technology , Wiedner Hauptstrasse 8-10/052, A-1040 Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Stöger-Pollach
authors.affiliation: University Service Centre for Transmission Electron Microscopy (USTEM), Vienna, University of Technology , Wiedner Hauptstrasse 8-10/052, A-1040 Vienna, Austria.
authors.forename: Walid
authors.initials: W
authors.lastname: Hetaba
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Willinger
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: Xing
authors.initials: X
authors.lastname: Huang
authors.affiliation: Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Schuster
authors.affiliation: Institute of Physical Chemistry, University of Innsbruck , Innrain 52a, A-6020 Innsbruck, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Klötzer
authors.affiliation: Institute of Physical Chemistry, University of Innsbruck , Innrain 52a, A-6020 Innsbruck, Austria.
authors.forename: Simon
authors.initials: S
authors.lastname: Penner