1,720,985 research outputs found
Fe2O3 Active phase for N2O decomposition: influence of the support nature on the properties and catalytic activity
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Temperature programmed desorption (TPD) of basic probe for the study of acid properties of iron oxide based catalysts
No full textNanostructured catalytic metal oxides supported over oxide supports of various nature : the iron oxide system
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Surface properties of dispersed Fe oxide catalytic phases supported over mesoporous silica
No full textPreparation and characterization of nanosized Fe-based heterogeneous catalysts on mixed oxide supports
No full textHighly concentrated and dispersed Fe oxide catalysts characterized by Mössbauer spectroscopy
No full textKinetics of reduction of supported nanoparticles of iron oxide
No full textA series of catalysts prepared by dispersing iron oxide on supports of different nature and acidity has been studied. Silica (S) and
silica-zirconia mixed oxides (SZ) with different ZrO2 content (from 5 to 45 mass%) were used as supports for the iron oxide phase which was deposited over them by an equilibrium-adsorption method. The red-ox properties of the Fe-catalysts were studied by temperature programmed reduction (TPR) technique.
The two well defined and narrow TPR peaks observed could be associated with the reduction steps: I) Fe2O3 -> FeO and
Fe2O3 -> Fe(0) (at ca. 400°C) and II) FeO -> Fe(0)(at ca. 800–900°C). The temperature of the second-step-peak increased with the
zirconia content in the support, likely because of the stronger interaction of the iron oxide phase with the support. Activation parameters for the two step-reduction processes were obtained by a simple computation procedure applied to the TPR profiles
A new, Fe based, heterogeneous Lewis acid : selective isomerization of a-pinene oxide
No full textHeterogeneous Fe supported catalysts prepared by grafting Fe(III) acetylacetonate under basic conditions onto pure silica and a series of modified silicas with variable amount of zirconia were prepared. Their characterization showed the presence of Fe3+ species, with complete surface dispersion of the iron-phase and without any Fe3O4 presence. These materials exhibit not only excellent activity in the liquid phase isomerization of a-pinene oxide but also good selectivity towards campholenic aldehyde, thus showing their Lewis acid
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Exceptional dispersion of high loaded Fe oxide on ceramic matrixes : characterization and activity in acid reactions
No full textIn the present work, amorphous catalysts containing nanosized Fe oxide phase at wide concentration (from 4 to 24 mass %) and high dispersion on ceramic oxides of different nature and characteristics (silica, alumina, niobia, zirconia, and mixed compositions), were synthesized and characterized. The influence of the support, Fe-precursor, and preparative methodology on the surface properties, Fe-dispersion, and catalytic activity of the samples has been investigated and rationalized with the final aim of better controlling the catalytic properties of the studied samples. The catalytic materials exhibited excellent activity in the liquid phase isomerization and acylation reactions
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