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La0.7Sr0.3CuO3−δ: An Interesting Catalyst for Methanol and Ethanol Treatment
No full textThe reactivity of La0.7Sr0.3CuO3-δ with methanol and ethanol was investigated in oxidation and steam reforming. The conversion is higher in the oxidation reactions (about 100 %) than in steam reforming (78% for methanol, 23% for ethanol). Significant amounts of hydrogen are observed during methanol steam reforming. Acetaldehyde forms with ethanol
La0.6Sr0.4Co0.8Fe0.2O3-delta and Fe2O3/La0.6Sr0.4Co0.8Fe0.2O3-delta powders: XPS characterization
No full textA Sr and Fe doped lanthanum cobaltate was prepared by wet chemistry procedure (Pechini) and compared with a nanocomposite system obtained by depositin iron oxide on the surface of the perovskite by wet impregnation. The investigation of both the systems was carried out by means of XPS
Steam reforming and oxidative steam reforming of methanol and ethanol: The behaviour of LaCo0.7Cu0.3O3
No full textLaCo0.7Cu0.3O3 perovskite powder was prepared by means of the citrate method and treated at different
temperatures from 873 to 1323 K. The samples were characterized by X-ray photoelectron spectroscopy
(XPS), X-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed
desorption (TPD, O2-TPD), and scanning electron microscopy (SEM); the BET specific surface area was
also determined. The reactivity of the perovskite with methanol and ethanol was investigated under
steam reforming and oxidative steam reforming conditions and correlated to its chemical and structural
properties. Different oxygen/alcohol molar ratios were used to study the influence of oxygen on catalytic
activity and products distribution. LaCo0.7Cu0.3O3 begins to be active in alcohol steam reforming at about
523 K. The catalyst calcined at 873K shows the higher conversion in methanol steam reforming. Ethanol
steam reforming conversion, in contrast, is rather low and not significantly affected by the catalyst calcination
temperature. The conversions increase when oxygen is present reaching 93% for methanol and
78% for ethanol. Beside the steam reforming and oxidative steam reforming, other secondary reaction
paths occur: methanol decomposition and ethanol dehydrogenation
Effect of the preparation procedure on the surface properties of nanosized ceria powders
No full textNanosized cerium (IV) oxide powders were synthesized using three different preparation
procedures: 1 precipitation from a basic solution of cerium nitrate containing H2O2 at 273 K; 2
Marcilly method, and 3 microemulsion method. In this work the influence of the preparation
procedure on the surface properties is studied by means of XPS. Besides the wide scan spectrum,
detailed spectra for the Ce 3d, Ce 4d, O 1s and C 1s regions and relative data are presented and
discussed
Oxygen Permeation Measurements: An Alternative tool to Select New Intermediate Temperature Solid Oxide Fuel Cell Cathodes
No full textIn this contribution four perovskite-based mixed ionic-electronic conductors (MIEC): a strontium
and iron doped lanthanum gallate (La08Sr02Ga08Fe02O3, hereafter LSGF8282), and strontium
or cobalt doped lanthanum cuprates (La07Sr03CuO3–LSC7310, La2Cu08Co02O4–LCC2082 and
LaCu03Co07O3–LCC1037), were synthesized by means of a wet-chemistry routes (Pechini method)
and characterized by X-Ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), specific
surface area (by the BET single point method) and Scanning Electron Microscopy (SEM). The oxygen
permeation properties were investigated by means of a home made permeation chamber at
600, 700 and 800°C in order to evaluate their applicability as cathode materials in intermediate temperature
solid oxide fuel cells (IT-SOFCs). The synthetic procedure allowed to achieve the desired
compounds, as confirmed by XRD and XPS measurements. The A2BO4-type sample (LCC2082)
showed higher oxygen permeation rate than ABO3 perovskites. This is ascribed to the oxygen
transportation extra contribution through the AO planes present in A2BO4 compound. Among the
ABO3-type samples, the copper-rich ones showed the most interesting oxygen permeation
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