Preparation and properties of nanophase (Ce, Zr, Pr)O2-doped alumina coating on cordierite ceramic honeycomb for three-way catalysts

Nanophase (Ce, Zr, Pr)O2-doped alumina coatings were prepared by impregnating the cordierite ceramic honeycomb in the sol or in the slurry of already calcined powder, respectively. The effects of preparation methods on the crystal phase, texture, oxygen storage capacity (OSC), reducibility, surface morphology and thermal stability of coatings were investigated by X-ray diffraction (XRD), the Brunauer Emmet Teller (BET) method, the oxygen pulsing technique, H2-temperature-programmed reduction (H2-TPR) and scanning electron microscopy (SEM). These nanophase (Ce, Zr, Pr)O2-doped alumina coatings were used as supports to prepare Pd-only three-way catalysts, and evaluated with respect to catalytic activities. The results indicate that the nanophase (Ce, Zr, Pr)O2-doped alumina coatings prepared by the two methods have high thermal stability. However, the coating derived from the sol shows better crystalline structure, texture, reducibility and oxygen storage capacity than the coating derived from the slurry. SEM observation shows that the morphology of the coating derived from the sol is uniform and smooth. The Pd-only catalyst derived from the sol exhibits high three-way catalytic activity at low temperature and thermal stability, suggesting a great potential for applications

Systems Biology approach to metabolomics in cancer studies

The astonishing development of high-throughput techniques in the last decades has fostered a renewed, dynamical comprehension of cell and tissue metabolism, giving unexpected insights into the ‘systemic aspects’ of cancer, namely pointing out that metabolism should be considered a truly “systems property. Both internal and microenvironmental cues tightly cooperate in shaping tissue metabolomic fingerprint. tumour metabolome hardly could be mechanistically linked to the linear dynamics of few gene regulatory networks; otherwise it is likely to be the complex end point of several interacting non-linear pathways, involving both cells and their microenvironment. As such, tumour metabolism might be considered an emerging, “systems property”, arising at the integrated scale of the whole system and behaving like an “attractor” in a specific space phase defined by thermodynamic constraints . Therefore, metabolomics ‘strategies’ are settled in order to understand complex biological systems from an integrated (‘holistic’) point of view. Metabolomics measurements are hence correlated with the time-dependent changes in concentrations of other components (proteins, gene-expression data), in order to obtain an integrated model of the gene-protein-metabolite interactions. Such framework represents a meaningful discontinuity with respect to the reductionist and qualitative molecular biology, and discloses new perspective to scientific researc

Structural, Surface, and Catalytic Properties of Aluminas

The published data concerning the structural, surface, and catalytic properties of aluminas are reviewed, and these properties are related to the preparation procedures. The experimental and computational investigations of the structural characteristics of the polymorphs most useful for applications in catalysis, which are \u3b3-, \u3b7-, \u3b4-, and \u3b8-Al2O3, are critically analyzed. The thermodynamics of the various polymorphs and the kinetics of the phase transitions are considered. The available information on Br\uf8nsted sites (i.e., hydroxyl groups), Lewis acid sites, and acid\u2013base pairs othe surface of aluminas is discussed. Data regarding the application of aluminas as a catalyst and as a catalyst support are summarized. Suggestions for future research are proposed