title: Three-dimensional microstructural imaging of sulfur poisoning-induced degradation in a Ni-YSZ anode of solid oxide fuel cells.
abstract: Following exposure to ppm-level hydrogen sulfide at elevated temperatures, a section of a solid oxide fuel cell (SOFC) Ni-YSZ anode was examined using a combination of synchrotron-based x-ray nanotomography and x-ray fluorescence techniques. While fluorescence measurements provided elemental identification and coarse spatial mapping, x-ray nanotomography was used to map the detailed 3-D spatial distribution of Ni, YSZ, and a nickel-sulfur poisoning phase. The nickel-sulfur layer was found to form a scale covering most of the exposed nickel surface, blocking most fuel reformation and hydrogen oxidation reaction sites. Although the exposure conditions precluded the ability to develop a detailed kinetic description of the nickel-sulfur phase formation, the results provide strong evidence of the detrimental effects of 100 ppm hydrogen sulfide on typical Ni-YSZ anode materials.
authors.affiliation: 1] HeteroFoaM Center, a DOE Energy Frontier Research Center [2] Department of Mechanical Engineering, University of Connecticut.
authors.forename: William M
authors.initials: WM
authors.lastname: Harris
authors.affiliation: 1] HeteroFoaM Center, a DOE Energy Frontier Research Center [2] Department of Mechanical Engineering, University of Connecticut.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Lombardo
authors.affiliation: 1] HeteroFoaM Center, a DOE Energy Frontier Research Center [2] Department of Mechanical Engineering, University of Connecticut.
authors.forename: George J
authors.initials: GJ
authors.lastname: Nelson
authors.affiliation: Advanced Photon Source, Argonne National Laboratory.
authors.forename: Barry
authors.initials: B
authors.lastname: Lai
authors.affiliation: Advanced Photon Source, Argonne National Laboratory.
authors.forename: Steve
authors.initials: S
authors.lastname: Wang
authors.affiliation: Advanced Photon Source, Argonne National Laboratory.
authors.forename: Joan
authors.initials: J
authors.lastname: Vila-Comamala
authors.affiliation: 1] HeteroFoaM Center, a DOE Energy Frontier Research Center [2] School of Materials Science and Engineering, Georgia Institute of Technology.
authors.forename: Mingfei
authors.initials: M
authors.lastname: Liu
authors.affiliation: 1] HeteroFoaM Center, a DOE Energy Frontier Research Center [2] School of Materials Science and Engineering, Georgia Institute of Technology.
authors.forename: Meilin
authors.initials: M
authors.lastname: Liu
authors.affiliation: 1] HeteroFoaM Center, a DOE Energy Frontier Research Center [2] Department of Mechanical Engineering, University of Connecticut.
authors.forename: Wilson K S
authors.initials: WK
authors.lastname: Chiu