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@PHDTHESIS{Deibert:255746,
      author       = {Deibert, Wendelin},
      title        = {{E}ntwicklung von geträgerten protonenleitenden
                      {D}ünnschichtmembranen für die {W}asserstoffabtrennung},
      volume       = {283},
      school       = {Universität Bochum},
      type         = {Dr.},
      address      = {Jülich},
      publisher    = {Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag},
      reportid     = {FZJ-2015-05860},
      isbn         = {978-3-95806-082-1},
      series       = {Schriften des Forschungszentrums Jülich Reihe Energie $\&$
                      Umwelt / Energy $\&$ Environment},
      pages        = {XI, 117 S.},
      year         = {2015},
      note         = {Universität Bochum, Diss., 2015},
      abstract     = {Hydrogen separation membranes offer a promising possibility
                      to separate pure hydrogen from gas mixtures. Ceramic
                      membranes from La$_{6-x}$WO$_{12-\delta}$ (LWO) are suitable
                      for this application, because the separation in membrane
                      reactors can take place at temperatures of more than 900
                      °C. LWO membranes are thermochemical stable under the
                      existent operation conditions. To reduce the transport
                      resistance, the membrane thickness has to be reduced, but
                      that leads to a decrease of the mechanical stability. The
                      solution for this is an asymmetric membrane architecture
                      consisting of a thin dense membrane layer and a porous
                      substrate. Though, a possible drawback is bending of the
                      two-layered structures during sintering. The first part of
                      this thesis deals with the synthesis and pre-treatment of
                      the ceramic powders, as well as with the manufacturing of
                      single membrane and substrate layers from LWO. The single
                      layers are analysed regarding their sintering behaviour.
                      Based on these findings, asymmetric two-layer systems
                      consisting of membrane and substrate (thicknesses of 20 and
                      200 $\mu$m) are produced by the sequential tape casting. A
                      detailed analysis of the sintering behaviour, the
                      microstructure, and a comparison between single layers and
                      two-layer assemblages is performed. Thereupon, further
                      successful developments of the temperature programme and the
                      substrate thickness are made. The bending of the two-layered
                      system is eliminated as far as possible by these procedures.
                      Another part of the thesis deals with magnesium oxide (MgO)
                      as an alternative substrate material, because of its
                      economic advantages over the manufacturing from LWO. For
                      this purpose, single layers and two-layer assemblages with a
                      MgO substrate are analysed regarding their chemical
                      stability, their sintering behaviour, and their
                      microstructure. It is shown that in future MgO can be used
                      as a cheap substrate material. For an increase of the
                      hydrogen flux the membrane material is modified by the
                      substitution of tungsten by Mo and Re. Two-layer assemblages
                      consisting of substituted membranes and different substrates
                      from LWO and MgO are investigated concerning the formation
                      of undesired secondary phases. Solely the combination of a
                      Mo-substituted LWO membrane with a LWO substrate is suitable
                      for further use. All other combinations cannot be
                      manufactured defect free. To prevent the membranes from
                      damage by chemical reaction with the substrate, intermediate
                      layers have to be integrated as diffusion barrier when using
                      MgO substrates. Finally, a hydrogen permeation measurement
                      executed with a two-layer assemblage from pure LWO, is
                      presented. The hydrogen flux is around 0.1 ml min$^{-1}$
                      cm$^{-2}$ at 775°C, which means an increase by a factor of
                      4 compared to bulk membranes.},
      cin          = {IEK-1},
      cid          = {I:(DE-Juel1)IEK-1-20101013},
      pnm          = {899 - ohne Topic (POF3-899) / HITEC - Helmholtz
                      Interdisciplinary Doctoral Training in Energy and Climate
                      Research (HITEC) (HITEC-20170406)},
      pid          = {G:(DE-HGF)POF3-899 / G:(DE-Juel1)HITEC-20170406},
      typ          = {PUB:(DE-HGF)11 / PUB:(DE-HGF)3},
      url          = {https://juser.fz-juelich.de/record/255746},
}