| 1. |
- Carlsson, A, et al.
(författare)
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The first structure determination of nanosized colloidal particles of Pd3P by high-resolution electron microscopy
- 1998
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Ingår i: Angewandte Chemie (International edition). - 1433-7851. ; 37:9
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Tidskriftsartikel (refereegranskat)abstract
- The exact three-dimensional structure of a nanosized colloidal particle of Pd3P was determined directly from high-resolution transmission electron microscopy (HRTEM) images that were recorded in several crystallographic directions. An HRTEM image recorded along [011] is shown on the right. The cores of the particles were excluded from the analysis because of severe multiple diffraction.
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| 2. |
- Larsson, Per-Olof, et al.
(författare)
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Combustion of CO and toluene; Characterisation of copper oxide supported on titania and activity comparisons with supported cobalt, iron, and manganese oxide
- 1996
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Ingår i: Journal of Catalysis. - : Elsevier BV. - 1090-2694 .- 0021-9517. ; 163:2, s. 279-293
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Tidskriftsartikel (refereegranskat)abstract
- Titania-supported copper oxide catalysts have been prepared with loadings in the range from 1/3 to 5 theoretical layers and have been tested for the combustion of CO and toluene. Characterisation with XRD, electron microscopy, EDX, TPR, Raman, and XPS gives details about the structure of copper oxide on titania. The results show that dispersed CuOx is formed up to a loading of about one theoretical layer. TPR indicates the formation of two types of dispersed species, which possibly are isolated and polymeric, respectively. XPS data show that the dispersed copper is Cu2+. Th, dispersed species have high catalytic activity for combustion. At higher copper oxide loading, bulk CuO is formed, contributing little to the activity. Comparison of three titania supports with differing surface area and pore size distribution shows that the most favorable is a support with a surface area of about 38 m(2)/g and mesopores in the range 100-800 Angstrom. The longevity of the catalysts was tested in the waste gas from a formaldehyde plant. Deactivation was observed after being on stream for 57 days, and the deactivation is due to sintering of both the support and the copper oxide. Copper oxide on titania is shown to be more active than cobalt, manganese, and iron oxide on the same support. (C) 1996 Academic Press, Inc.
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| 3. |
- Oku, Takeo, et al.
(författare)
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Digital HREM imaging of yttrium atoms in YB56 with YB66 structure
- 1998
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Ingår i: Journal of Solid State Chemistry. - : Elsevier BV. - 0022-4596. ; 135:2, s. 182-193
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Tidskriftsartikel (refereegranskat)abstract
- The arrangement of yttrium atoms in YB56with YB66structure was determined by high-resolution electron microscopy (HREM) using a slow-scan CCD camera. Digital HREM images recorded along the [100], [110], and [111] directions of the YB56crystals showed "averaged" yttrium atom positions in the boron clusters, which were also confirmed by image simulation. Digital HREM images recorded from thin regions (
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| 4. |
- Skårman, Björn, et al.
(författare)
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Carbon monoxide oxidation on copper oxide thin films supported on corrugated cerium dioxide {111} and {001} surfaces
- 1999
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Ingår i: Journal of Catalysis. - : Elsevier BV. - 1090-2694 .- 0021-9517. ; 181:1, s. 6-15
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Tidskriftsartikel (refereegranskat)abstract
- Thin films of CeO2 with and without a thin layer of copper oxide were prepared by rf magnetron sputtering on surfaces of alpha-Al2O3 (sapphire) substrates. Careful characterisation of the surfaces was performed down to the atomic level using high-resolution electron-microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Surprisingly, the as-deposited, corrugated ceria surfaces, nominally (001), consist exclusively of {111}-type lattice planes, but, upon annealing at 800 degrees C, a well-defined portion of (001) surfaces are formed. Oxidation of carbon monoxide to carbon dioxide was studied, having the prepared films in a stirred batch reactor. A batch reactor was chosen so that the conversion over the small sample surface area (ca 10(-4) m(2)) could be monitored as a function of the reaction time. The activity of copper oxide on annealed ceria surfaces is markedly higher than on nonannealed surfaces, indicating a favourable synergetic effect between the ceria (001) surface and the copper oxide phase. (C) 1999 Academic Press.
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