Inorganic Microporous Membranes for Gas Separation in Fossil Fuel ...

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4 Results and discussion Raman Intensity Table 28 Raman bands of the TiO2 and ZrO2 membrane assigned to the microstructural phases. 138 (s: strong, w: weak, vw: very weak). Laser excitation TiO2 membrane ZrO2 membrane 514.5 nm, 40.1 mW 632.8 nm, 4.8 mW Wavelenth in cm -1 520 520w 522w Anatase TiO2 468vw Monoclinic ZrO2 450vw 453vw Monoclinic ZrO2 or Rutile TiO2 432w 433w α-Al2O3 α-Al2O3 419s 419s α-Al2O3 α-Al2O3 380s 381s α-Al2O3 α-Al2O3 148s 148s Anatase TiO2 468 450 432 419 A -- TiO2 -- ZrO2 B 381 148 500 400 300 200 100 Wavenumber/cm -1 101 Raman Intensity 522 453 433 419 374 148 500 400 300 200 100 Wavenumber/cm -1 Figure 68 Raman spectra of TiO2 (red) and ZrO2 (brown) membranes calcined at 500ºC. Excitation: A) 514.5 nm, 40.1 mW and B) 632.8, 4.8mW. Figure 69-B presents a homogeneous thin 25-30 nm ZrO2 layer containing ordered zirconium atoms (Figure 69-A). No particles and pores could be observed. Ordered ZrO2 was observed in the scale of the membrane layer thickness indicating fully crystalline layer. Fully crystalline 25 nm thin layers with the absence of small particles might form a gastight layer. The presence of these ZrO2 nanocrystals might explain the rather small BET specific surface area due to the inaccessibility of N2. The electron diffraction pattern obtained from the HR-TEM analysis on the ZrO2 membrane calcined at 500ºC showed crystalline and amorphous intensity. The
4 Results and discussion amorphous intensity originates from the supporting γ-Al2O3 layer and the nanocrystalline intensity to tetragonal ZrO2 phase as could expected from the XRD results on powders. Raman spectroscopy presents mainly alumina (Table 28 and Figure 68). Monoclinic ZrO2 enrichments on the surface might be identified by the very weak band at 468 and 450 cm -1 . Tetragonal ZrO2 bands (e.g. 370 cm -1 ) are hard to distinguish because this band is in the same wave number region where the α-Al2O3 bands are observed. Raman studies with 488 nm excitation on both TiO2 and ZrO2 membranes could not reveal more contrast. A ZrO2 γ-Al2O3 Figure 69 A and B) TEM images of a ZrO2 membrane calcined at 500ºC supported by γ-Al2O3. Cross section TEM image show 20-30 nm Ti0.5Zr0.5O2 membranes that are calcined at 500 and 600ºC. Both membranes obtain amorphous structures. The electron diffraction patterns obtained by TEM do not indicate the presence of crystalline domains in the Ti0.5Zr0.5O2 layer calcined at 500 and 600ºC. The absence of orthorhombic Ti0.5Zr0.5O2 which can be observed by XRD at 600ºC in the bulk material can be the result of effects that result from interactions between the layer and the support material. Raman spectroscopy demonstrates mainly alumina. No clear trends are observed on the difference in calcination temperature of the membranes. The weak band at 450 cm -1 , at both the laser excitations, can either be assigned to rutile TiO2 or to monoclinic ZrO2 (Table 29 and Figure 71). Raman spectroscopy could not show any signs for tetragonal ZrO2, anatase TiO2 or orthorhombic TiZrO4. Ti-O-Al, Zr-O-Al or Ti-O-Zr 139 bands were not visible. 102 Tungsten ZrO2 γ-Al2O3 B
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Mitglied der Helmholtz-Gemeinschaft
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Forschungszentrum Jülich GmbH Inst
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List of Abbreviations Ac Acetyl Ace
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Summary CO2 capture and storage mig
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Zusammenfassung Die Abtrennung und
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Content Content CONTENT............
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1 Introduction and aims 1 Introduct
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1 Introduction and aims Candidate m
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2 Theoretical background 2 Theoreti
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2 Theoretical background Despite th
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2 Theoretical background Table 2 Ox
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2 Theoretical background 2.1.2 Micr
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2 Theoretical background Poly-cryst
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2 Theoretical background membranes
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2 Theoretical background Dry or wet
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2 Theoretical background the materi
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2 Theoretical background Figure 9 D
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2 Theoretical background Figure 11
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2 Theoretical background due to its
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2 Theoretical background 2.3.3.2 Mi
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2 Theoretical background 2.4 Microp
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2 Theoretical background Figure 15
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2 Theoretical background wall inter
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3 Experimental 3 Experimental The m
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3 Experimental vacuum sample holder
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3 Experimental o of as-made DOH cry
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3 Experimental Another solution was
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3 Experimental 3.4 Characterisation
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3 Experimental Element analysis The
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3 Experimental Additionally, the hy
Page 62 and 63: 4 Results and discussion Abundance
Page 64 and 65: 4 Results and discussion 4.2 Zeolit
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Page 68 and 69: 4 Results and discussion hours usin
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Page 72 and 73: 4 Results and discussion The carbon
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Page 76 and 77: 4 Results and discussion 900 [ºC]
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Page 92 and 93: 4 Results and discussion DTA µV/mg
Page 94 and 95: 4 Results and discussion Vads / cm
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Page 100 and 101: 4 Results and discussion V micro /V
Page 102 and 103: 4 Results and discussion In pure Ti
Page 104 and 105: 4 Results and discussion In summary
Page 106 and 107: 4 Results and discussion Intensity
Page 108 and 109: 4 Results and discussion nanonic YS
Page 110 and 111: 4 Results and discussion ~50nm TiO2
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Page 126 and 127: 6 References 22. Shao, Z., Dong, H.
Page 128 and 129: 6 References 65. Van den Berg, A. W
Page 130 and 131: 6 References 108. Wen, T. L., Heber
Page 132 and 133: Curriculum Vitae - George van der D
Page 134: Last but not least, I would like to
Page 137: Band | Volume 8 ISBN 978-3-89336-52
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Inorganic Microporous Membranes for Gas Separation in Fossil Fuel ...

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