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The design of molecular materials suitable for disparate fields could lead to new advances in engineering applications. In this work, a series of Ln3+-doped BiF3 sub-microparticles were synthesized through microwave-assisted synthesis. The effects of doping are evaluated from the structural and morphological viewpoint. In general, increasing the Ln3+ concentration the octahedral habitus is distorted to a spheric one, and some aggregates are visible without any differences in the crystalline phase. The optical response of the samples confirms that the BiF3 materials are suitable hosts for the luminescence of the tested trivalent lanthanide (Ln3+) ions (Ln = Eu, Tb, Tm, Ho, Er, Yb). A Yb3+/Er3+ co-doped sample is presented as an illustrative example of all-photonic molecular logic operations and primary luminescent thermometry.

In the present study a series of Au–transition metal oxides supported on a clay mineral such as sepiolite were tested in the preferential oxidation of CO in an excess of H2 under simulated solar light irradiation and in the absence of light, at 30 °C and atmospheric pressure. Transition metal oxides (ZnO, Fe2O3, NiO, MnO2, and Co3O4) were dispersed over the sepiolite surface where, subsequently, Au nanoparticles with an average particle size between 2 and 3 nm were successfully deposited–precipitated. The obtained photocatalysts were characterized by XRD, XRF, DRUV-Vis, N2 adsorption–desorption and HRTEM in order to evaluate the optical, structural and chemical properties of the prepared samples. Despite the low amount of gold (nominal 1.0 wt%), the catalysts exhibited an outstanding behavior under light irradiation, with reaction rates between 4.5 and 5.2 mmol COox gcat−1 h−1 for the Au–NiSep, Au–CoSep and Au–ZnSep samples. These photocatalysts exhibited a high dispersion of the respective transition metal oxides over the sepiolite support and the presence of low-coordinated hemispherical gold nanoparticles. The superior photocatalytic efficiency of these samples was ascribed to the reduction of the electron–hole pair recombination of photogenerated charge carriers by the excitation of the localized surface plasmon resonance of the Au nanoparticles. The BET surface area and the gold particle size seemed to be relevant factors affecting the catalytic performance.

Ceria-doped titania photocatalysts (ceria loading 0.25–5.0 wt%) were synthesized by hydrothermal methods for water remediation. Nanotubes (CeTNTx) and nanoparticles (CeTNPx) were obtained. Ceria doping was applied to tune the electronic properties of nanostructured titania, boosting its photocatalytic activity. CeTNT nanostructures contained anatase as the only titania phase, whereas the CeTNP series consisted of both anatase and rutile polymorphs. The Ce addition induced a decrease in the energy gap, allowing enhancement of visible light harvesting. The photodegradation of methylene blue, MB, in aqueous solution was chosen to study the influence of the morphology and the ceria loading on the photocatalytic response, under UV and solar light. Both CeO2–TiO2 nanoparticles and nanotubes were found to be very active under UV light. The highest MB degradation rates were obtained for the 0.25 wt% CeO2 doping, for both nanotubes and nanoparticles (0.123 and 0.146 min−1, respectively), able to photodegrade completely the dye after 120 min. The two samples are stable after a 3-cycle reusability test. The photo-response under simulated solar light confirmed that doping titania with ceria allows harvesting visible light absorption, enhancing its photoactivity. A maximum efficiency of 85% under simulated sunlight at a degradation rate of 0.054 min−1 was obtained. Transient photoluminescence confirmed that MB acts as a charge scavenger for the composite system. These results pointed out ceria-doped titania nanostructures as a promising class of photocatalysts for the degradation of dyes and other hazardous organic compounds in wastewater.

Massive quantities of spent coffee grounds (SCGs) are generated by users around the world. Different processes have been proposed for SCG valorization, including pyrolytic processes to achieve carbonaceous materials. Here, we report the preparation of activated carbons through pyrolytic processes carried out under different experimental conditions and in the presence of various porosity activators. Textural and chemical characterization of the obtained carbons have been achieved through Brunauer–Emmett–Teller (BET), ESEM, 13C solid state NMR, XPS, XRD, thermogravimetric and spectroscopic determinations. The aim of the paper is to relate these data to the preparation method, evaluating the correlation between the spectroscopic data and the physical and textural properties, also in comparison with the corresponding data obtained for three commercial activated carbons used in industrial adsorption processes. Some correlations have been observed between the Raman and XPS data.

We investigated the effect of copper doping on the photocatalytic properties of TiO2 thin films. Titania thin films doped with three different copper concentrations were synthesized via radiofrequency-assisted (RF) magnetron sputtering, then annealed at 600 °C in controlled atmosphere (Ar, O2, H2 flow). The impact of the annealing in inert, oxidizing or reducing atmosphere on the crystalline and surface structure, and photocatalytic performance in the methylene blue degradation under UV light irradiation was investigated by X-ray diffraction, UV–Vis Spectroscopy, Rutherford Backscattering Spectrometry, Scanning Electron Microscopy. Annealing induced very different crystallization in different atmospheres, with strong copper out-diffusion in samples annealed in reducing atmosphere and formation of large embedded nanoparticles. The Cu-doped titania films exhibited higher photocatalytic activity than pure titania film and the best performing catalyst, treated in H2 atmosphere, suggests that the presence of embedded copper nanoparticles (both metallic and oxidized) is able to strongly enhance the photocatalytic properties of the host titania matrix. Incorporated Cu particles can act as trapped sites for generated electrons, and this leads to the reduction of carrier recombination which, ultimately, plays a significant role in the increase of photoactivity. The recyclability of the best system was ascertained by a suitable 3-cycle stability test.

Gold nanoparticles precipitated-deposited on titania nanostructures (1.0 wt% nominal loading) were studied in the preferential CO oxidation in excess of H2 at room temperature and atmospheric pressure, both in dark and under simulated solar light irradiation. Titania supports were synthesized by means of two hydrothermal methods markedly acid and basic, giving rise to rutile nanorods and anatase deformed nanorods structures, respectively. Characterization techniques such as N2 physisorption, XRD, XPS, DRUV-vis, HRTEM and XRF were performed in order to study the chemical, structural and optical properties of the catalysts. Well defined rutile nanorods structures were obtained from the acidic treatment allowing a regular distribution of gold nanoparticles and resulting quite active in the CO-PROX reaction. In particular the sample from the acidic synthetic approach calcined at 700 °C displayed the best results as it was highly selective to CO2 under both dark and simulated solar light irradiation.

In this study the photo-response behaviour of Au/TiO2 systems in the preferential CO oxidation in a H2-rich stream (CO-PROX) was investigated by the first time under simulated solar light irradiation at room temperature and atmospheric pressure. Au nanoparticles, with an average size of 2–5 nm, were precipitated-deposited on a mesoporous TiO2, previously synthesized by sol-gel type procedure and thermally treated at different temperatures to obtain anatase/rutile mixed phases. Structural, chemical and optical properties were studied by means of AAS, N2 physisorption, XRD, HR-TEM, DRUV–vis and XPS, investigating the effects of TiO2 polymorphs (anatase, rutile and combination thereof). All samples, containing a very low amount of noble metal (0.5 wt%), resulted very active in the photocatalytic CO-PROX at ambient conditions, attaining very high CO conversion and CO2 selectivity values. The Au/TiO2 sample containing both anatase/rutile polymorphs in the support displayed the highest activity, both in dark and under simulated solar light, due to the simultaneous presence of these two titania crystalline phases, capable to lower the effective band gap of the composite system (2.90 eV) and improving the photocatalytic activity in the studied reaction. This kind of materials may provide a sustainable and feasible approach to selectively oxidize CO in H2-rich stream under solar light irradiation and ambient conditions.

A study was conducted to investigate the effect of the preparation route of ZrO2 in CuO–CeO2/ZrO2 catalysts for the oxidation of carbon monoxide at low temperature (COX). Four ZrO2 supports were synthetized via either type sol-gel methodology or precipitation. The final Cu-Ce-Zr oxide catalysts were prepared by incipient wetness co-impregnation with copper and cerium solutions (with a loading of 6 wt% of CuO and 20 wt% of CeO2). The catalyst crystalline phases, texture and active species reducibility were determined by XRD, N2 physisorption at −196 °C and H2-TPR, respectively; meanwhile the surface composition and copper-cerium electronic states were studied by XPS. The catalytic activity was evaluated in the oxidation of CO to CO2, in the 40–215 °C temperature range. Catalytic results evidenced that the samples prepared by a sol-gel methodology showed, after the impregnation, a severe decrease of specific surface area and pore volume attributable to a wide degree of pore blockage caused by the presence of metal oxide particles and a collapse of the structure partially burying the active sites. A simple co-impregnation of a zirconia support, obtained through facile and fast precipitation, provided instead a catalyst with very good redox properties and high dispersion of the active phases, which completely oxidizes CO in the range 115–215 °C with T50 of 65 °C. This higher observed activity was ascribed to the formation of a larger fraction of highly dispersed and easily reducible Cu species and ceria nanocrystallites, mainly present as Ce(IV), with an average size of 5 nm.

We investigated the photocatalytic behavior of gold nanoparticles supported on CeO2-TiO2 nanostructured matrixes in the CO preferential oxidation in H2-rich stream (photo-CO-PROX), by modifying the electronic band structure of ceria through addition of titania and making it more suitable for interacting with free electrons excited in gold nanoparticles through surface plasmon resonance. CeO2 samples with different TiO2 concentrations (0-20 wt %) were prepared through a slow coprecipitation method in alkaline conditions. The synthetic route is surfactant-free and environmentally friendly. Au nanoparticles (

During the last two decades, Dye Sensitized Solar Cells (DSSCs) have received a great deal of attention as a promising, low-cost alternative to conventional silicon photovoltaic devices. Natural dye molecules can be used as a sensitizer for their low cost, good light absorbance, easy preparation process, and biodegradability. In this study, dyes were obtained from wine lees, the last by-product of winemaking process, supplied by a venetian winery (Italy). Polyphenols, like tannins and anthocyanins, which were extracted from winemaking lees, were adsorbed on a nanostructured ordered mesoporous titanium dioxide, previously treated at different temperatures (400&ndash, 600 &deg, C). Both dyes and titania semiconductor samples were studied with different techniques. The tests were carried out on prototypes to evaluate the cell power and the photocurrent generated under simulated solar light irradiation. The obtained solar energy conversion efficiencies are comparable to those that were reported in literature by using organic dyes extracted from vegetables, fruits, and plants. It is significant that these dyes are largely available and cost effective, since recovered from a waste otherwise to be disposed of, opening up a perspective of feasibility for inexpensive and environmentally friendly dye solar cells to generate green electricity and transforming agri-food waste into a resource.

Mixed ceria–zirconia oxide (CZ91, Ce:Zr = 9:1) has been used to support Nickel (CZ91Ni), Cobalt (CZ91Co) and bimetallic Nickel/Cobalt active phases (CZ91NiCo) to be tested in Ethanol Steam Reforming reaction (ESR). H 2 -TPR analyses and IR studies of adsorbed probe molecules suggest that ceria/zirconia actually favors the reduction of supported metal oxide phases. Moreover, characterization results point out that the co-presence of Nickel and Cobalt, as in the CZ91NiCo material, enhances the reducibility of both the metal oxide phases, in comparison with monometallic formulations, thus suggesting a synergetic effect between Cobalt and Nickel species. Correspondingly, bimetallic CZ91NiCo catalyst shows the best results in ESR in terms of ethanol conversion, hydrogen yield and selectivity to CO 2 above 500 °C, which should be explained by the high reducibility of this sample. Ethene formation was not detected in significant amount during catalytic tests. Indeed, the basicity of ceria component is mainly characterizing the surface of this family of catalysts.

CuO supported on CeO2, Ce0.8Zr0.2O2 and Ce0.8Al0.2O2 based catalysts (6%wt Cu) were synthesized and tested in the preferential oxidation of CO in a H2-rich stream (CO-PROX). Nanocrystalline supports, CeO2 and solid solutions of modified CeO2 with zirconium and aluminum were prepared by a freeze-drying method. CuO was supported by incipient wetness impregnation and calcination at 400 � C. All catalysts exhibit high activity in the CO-PROX reaction and selectivity to CO2 at low reaction temperature, being the catalyst supported on CeO2 the more active and stable. The influence of the presence of CO2 and H2O was also studied.

The application of the catalytic system CuO/CeO2 supported on Zr doped SBA-15 mesoporous silica to the preferential oxidation of CO on hydrogen streams (CO-PROX) suitable to be used to feed PEM fuel cells, has been studied. A loading of 20% (wt.) Ce and 6% (wt.) Cu was found optimal for the CO-PROX reaction. The influence of the presence of CO2 and H2O in the gas feed was also studied in order to simulate the real operation conditions of a PEMFC feed stream generated by alcohol steam reforming. The catalysts were characterized by XRD, adsorption–desorption of N2 at −196 ◦ C, TEM, –H2-TPR and XPS. The system reducibility was found modified by the incorporation of zirconium in the support, with improvement of both the conversion and selectivity of the catalytic system, compared to the same material without Zr. © 2010 Elsevier B.V. All rights reserved.

Nanostructured Au/Al(2)O(3)-CeO(2) catalysts with a low content of precious metal (0.9% wt.) were prepared immobilizing two different stabilized Au sols on a high surface area Al(2)O(3)-CeO(2) mixed oxide with a uniform pore size distribution, synthesized by a one-pot methodology. The samples were characterized by elemental analysis, N(2) physisorption, XRPD, TEM and (27)Al-MAS NMR techniques. The catalytic activity of the two samples in the preferential oxidation of CO in excess of H(2) (CO-PROX) was comparatively evaluated in the 35-110 degrees C temperature range. The Au-THPS/AlCe20 sample, prepared immobilizing a sol obtained reducing an aqueous solution of gold tetrachloroaurate salt with bis[tetrakis(hydroxymethyl)phosphonium sulfate], resulted very active and selective at low temperatures and its catalytic activity was correlated with the structural characteristics of the metal particles and of the ordered mesoporous support.

In this work, SBA-15 silica and silica-titania have been used as supports for photocatalysts based on AuCu alloy (Au:Cu = 1) to be used in the preferential oxidation of CO (CO-PROX) in excess of hydrogen at room temperature and atmospheric pressure both in the dark and under simulated solar light irradiation. To study their textural, structural, chemical and optical properties, the samples were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), adsorption-desorption of N2 at &minus, 196 &deg, C, 13C and 29Si solid state nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance ultraviolet-visible (DRUV-vis) spectroscopy. Titanium was present mainly in the form of titania aggregates, but also as small particles interacting with the SBA support. In both catalysts, the metal alloy nanoparticles displayed an average size of 4 nm as demonstrated by TEM measurements. AuCu/Ti-SBA turned out to be photoactive and selective in the photo-CO-PROX reaction showing the highest activity, with conversion and selectivity towards CO2 of 80%, due both to the presence of titania incorporated in SBA-15 and to the synergistic effect of Cu when alloyed with Au.

A new synthesised triphenylamine-based dye having a branched structure with one OH-ending branch able to interact with the surface hydroxyl moieties of mesoporous TiO2 is reported. Optical properties of the dye-titania hybrid material are presented and the higher efficiency of the dye on pure anatase TiO2 compared to the commercial Degussa P25, which contains a rutile phase component, is confirmed. The optical and chemical properties of the dye make it a promising candidate as a metal-free dye for DSSCs or as a host for a variety of transition or main group metal ions for different applications.

Natural kaolin was treated at 850 or 950 degrees C in air flow to give respectively the metakaolin samples MK8 and MK9. The obtained materials were successively treated at 90 degrees C with a 1 M solution of H(2)SO(4), for various time lengths. The acid treatment of MK8 was found to give a high surface area microporous material with good catalytic properties related to the high density of acid sites, while MK9 gave an ordered mesoporous material with a low density of acid sites. The materials were characterized by several techniques, X-ray powder diffraction, thermogravimetric analysis, N(2) physisorption, scanning electron microscopy, and temperature-programmed desorption of ammonia. The 1-butene isomerization was used as test reaction to evaluate the acidity of the samples.

A hybrid organic–inorganic material was prepared by surface initiated controlled/“living” radical polymerization (CRP) of styrene in the internal space of a MCM-41 silica. The inorganic precursor was synthesized, via sol–gel, using tetraethoxysilane and cetyltrimethylammonium bromide, in the presence of ammonia and ethanol to induce the formation of submicrometric spherical particles. After characterization by powder X-ray diffraction (XRD), transmission electron micrography (TEM), scanning electron micrography (SEM), N2 adsorption and titration of the surface silanol groups, the mesoporous silica was functionalized through a 3-step grafting process, in order to link the nitroxide initiator to the inorganic matrix (TEMPO-MCM-41). The anchorage of the TEMPO-based initiator was checked by diffuse reflectance infrared spectroscopy (DRIFT-IR). Experimental data confirmed that the styrene polymerization occurred inside the MCM-41 channels system.

A Cu/CeO2/Al2O3 catalyst prepared by a single-step sol–gel method was studied for methanol steam reforming (SRM) to gain information on the oxidation state of Cu and the role of oxidized Cu species. The catalyst was tested in a new laboratory-made flow apparatus that allowed on-line analysis of the products and measurement of the oxidation state and dispersion of Cu in situ. The catalyst pre-reduced in H2 was more active and selective than the not pre-reduced one. The oxidation state, evaluated after SRM tests, suggested the presence of a layer of oxygen atoms on the metallic Cu surface. Treating the pre-reduced catalyst with H2O vapour at 250 °C caused dissociative H2O chemisorption and led to a partial oxidation of Cu. The H2O oxidized sample reacted with CH3OH producing CO2 and H2 as long as oxygen was present on the Cu surface. The results support an oxidation–reduction mechanism.

Ce–Zr–Cu mixed oxide systems, with different contents of ZrO2 and CuO, were prepared by slow co-precipitation method, leading to the formation of materials with a flower-like morphology. It was evaluated both the role of CuO loading (3–7 wt%), by maintaining constant the amount of ZrO2 (7 wt%), and the role of ZrO2 (2–10 wt%) with a fixed amount of CuO (7 wt%). The prepared catalysts were characterized by means of ICP-OES, SEM, N2 physisorption, quantitative XRD, H2-TPR, and XPS. Their catalytic performances in the preferential oxidation of CO in excess of H2 (CO-PROX) were evaluated, in the 40–190 °C temperature range. Characterization and catalytic results showed that an optimum Zr/Ce molar ratio and CuO loading are required to attain the best catalytic performance over the studied nanostructured Ce/Zr/Cu oxide system. Characterization results revealed that, regardless of the sample composition, all of them presented similar flower-like morphology and textural properties. Instead, the catalyst composition determined the crystalline phases formed, their reducibility and surface distribution. The catalyst containing an intermediate ZrO2 loading (7 wt%) and the highest studied CuO amount (7 wt%), FCZCu77, showed the higher fraction of undetectable CuO from XRD, that is the highest proportion of highly dispersed Cu species also observed from H2-TPR. These characteristics justify how FCZCu77 catalyst exhibited a quite higher catalytic activity than the others samples.

The liquid phase hydrogenation of acetophenone was studied over a series of silica supported bimetallic catalysts with various Ru/Cr atomic ratios. The catalysts were prepared by reduction of the metal salts with NaBH4 aqueous solutions and were characterised by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) (ESCA). The hydrogenation reaction was carried out in batch at a hydrogen pressure of 9 bar. The selectivity towards reduction of the carbonyl function increases with the increasing amount of Cr ions added. © 2002 Elsevier Science B.V. All rights reserved.

Ordered mesoporous silica nanoparticles (MSNs) were impregnated with different loadings of the luminescent complex tris(dibenzoylmethane) mono(1,10-phenanthroline)europium(III) (Eu(dbm) 3 phen), with the aim of increasing the luminescence by avoiding concentration quenching and having mainly in mind the application as spectral converter for multi-crystalline silicon solar cells. The morphological, structural and luminescence properties of the impregnated silica nanoparticles were characterized by N 2 physisorption, X-ray diffraction, transmission electron microscopy, infrared spectroscopy, UV–visible spectroscopy and photoluminescence excitation and emission measurements. Photostability was tested under 1 sun (1000 W/m 2 ) illumination for 24 h and the related effects were inspected by UV–visible and photoluminescence spectroscopies. Impregnation of the complex into 50–70 nm MSNs with pore size tailored around 2.9 nm depressed concentration quenching and allowed the use of complex loadings as high as 23 wt%. Sunlight irradiation caused a marked increase in the luminescence intensity.

a b s t r a c t Nanocrystalline CeO2 with a regular size of 9.5 nm was prepared by a freeze-drying method, and subse- quent impregnated with a Cu(II) acetate solution, varying the loading of Cu (3, 6, 12 wt.%). The resulting CuO/CeO2 materials were characterized by N2 physisorption at −196 ◦ C, HRTEM, H2-TPR, X-ray diffrac- tion, Raman spectroscopy and XPS and tested as catalysts in the preferential CO oxidation in a H2-rich stream (CO-PROX) in the temperature range 40-190 ◦ C. In spite of their low specific surface areas the cat- alysts exhibited a good catalytic performance, resulting active and selective in the CO-PROX reaction at low temperatures. The inhibiting effect of the simultaneous presence of CO2 (15 vol.%) and H2O (10 vol.%) in the reaction mixture on the performance of CuO-CeO2 catalysts was also investigated. The addition of CO2 and water in the gas stream depressed CO oxidation up to 160 ◦ C, its effect being negligible at higher temperatures. Nevertheless, despite these expected deactivation phenomena, a CO conversion value higher than 90% and a CO2 selectivity of about 90% was achieved for all the samples at 160 ◦C. The excellent performance, especially shown by the catalyst with 6 wt%. of copper, has been related to the wide dispersion of the copper active sites associated with the high amount of Ce4+ species before reaction.

Ce–Cu and Ce–Zr–Cu oxide systems with a flower-like morphology were prepared by slow co-precipitation in the absence of any structure directing agent. For the sake of comparison, Ce–Cu and Ce–Zr–Cu oxide samples were also prepared by a classic co-precipitation method. All the samples were calcined in air flow at 650 °C. The materials were characterized by SEM and TEM microscopy, quantitative X-ray diffraction, N2 physisorption, H2-TPR, O2-TPD and XPS. The catalytic activity of the prepared samples was evaluated in the preferential oxidation of CO in excess of H2 (CO-PROX), in the 40–190 °C temperature range., The authors wish to thank Martina Marchiori (Ca’ Foscari University – Venice) for N2 physisorption and TPR-TPO measurements and Dr. Davide Cristofori (Ca’Foscari University-Venice) for the HRTEM measurements.

In this article, the preparation and application of gold and cerium catalysts supported on zirconium-doped mesoporous silica SBA-15 was studied. These materials have been prepared by two different methods and characterized to investigate their textural properties, dispersion of the active phases and oxidation states. Both materials exhibit a marked catalytic activity. The size of the gold nanoparticles is directly related to the CO conversion rate and to the selectivity towards CO 2 exhibiting a strong temperature dependence. An X-ray photoelectron spectroscopic study of the composition and chemical state of the nanoparticles indicates the presence of Au in a metallic state. Transmission electron microscopic micrographs indicate that the best catalyst shows a higher dispersion of Au in spite of its lower gold surface content.

Here we describe the step-wise grafting of the fluorophore dansyl chloride on the interlayer aluminol groups of kaolinite. The modified clay was characterized by powder RD, TGA, FT-IR and (27)Al, (19)Si, (13)C MAS-NMR, which confirmed the achievement of the clay functionalization. The photophysical properties of the resulting nanohybrid material were evaluated by photoluminescence excitation and emission measurements.

A Ce-Zr-Cu oxide system with a flower-like morphology was prepared by a slow co-precipitation method in the absence of any structure directing agent. Four portions of the oxide were thermally treated at four different temperatures (350°C, 450°C, 550°C, 650°C). The resulting materials samples were characterized by quantitative XRD, adsorption-desorption of N2 at-196°C, SEM and TEM microscopy, -H2-TPR, XPS and Operando-XANES. All samples were tested in the preferential CO oxidation (CO-PROX) in the 40-190°C temperature range. Thermal treatments were found to induce slight structural changes without altering the starting morphology of the samples. The samples treated at higher temperature 550-650°C showed a quite interesting CO-PROX activity and selectivity in a temperature range suitable for a practical use within the FEMFC technology. © 2011 Elsevier B.V.

A mesoporous Cu-Ce-Al-based material was prepared by a single-step synthesis, performed in n -propanol using aluminum sec -butoxide as Al precursor and metal stearates, both as Cu-Ce sources and structural directing agents. This type of synthetic approach appears to be very efficient for the preparation of highly dispersed Cu-Ce containing particles supported on a structurally ordered alumina with high surface area (>400 m 2 g −1 ) and quite narrow pore size distribution, as confirmed by X-ray powder diffraction, TPR and dispersion data and N 2 physisorption. The catalyst was also characterized by XPS and FT-IR measurements of adsorbed CO. The catalytic activity for the preferential oxidation of CO to CO 2 (PROX) in H 2 -rich streams was tested in the 75–200 °C temperature range.

Various samples of the Al–Ce–Cu ordered mesoporous oxide system were prepared by a single-step synthesis using n-propanol as solvent, aluminum sec-butoxide as Al precursor, metal stearates and/or metal nitrates as Cu and Ce sources. Different reagent types and reagents ratios were used in order to explore the role of these synthetic parameters in determining the chemical, textural and structural properties of the resulting materials. The study was carried out using nitrogen physisorption at 77 K, X-ray powder diffraction (XRPD), temperature-programmed reduction (H2-TPR), temperature-programmed desorption of ammonia (NH3-TPD) and FT-IR spectroscopy of adsorbed pyridine.

A series of CuO-ZnO/TiO2 ternary catalysts was prepared by co-precipitation and characterized by X-ray powder diffraction (XRPD), N2 physisorption at 77 K, temperature-programmed reduction/oxidation (H2-TPR/TPO) and FT-IR measurements of low temperature adsorbed CO. The catalysts were tested and found active in the preferential oxidation of CO (CO-PROX) in hydrogen-rich gas streams and their catalytic performance was compared with that of the binary systems CuO/ZnO and CuO/TiO2. © 2008 Elsevier B.V. All rights reserved.

An Al/Ce/Mg=50.0/1.0/1.0 atomic ratio (a.r.) pillared montmorillonite was used to support 1.0 wt.% of the bimetallic species Pd/Pt=5.0 and Pd/Au=5.0 a.r. The resulting catalysts were characterized by XRPD, N2 physisorption, ammonia TPD and FT-IR spectroscopy. The catalytic activity in the hydrogenation and hydrogenolysis/ring-opening of naphthalene and thio-tolerance to dibenzothiophene were investigated at 6.0 MPa in a flow reactor. Both catalysts showed interesting performances. Of the two catalysts, the former showed higher productivities in hydrogenation and hydrogenolysis/ring-opening compounds together with lower losses in carbon balance and higher thio-tolerance. These results not only confirmed that Pd/Pt is one of the most suitable bimetallic pair for noble metal containing hydrotreating catalysts, but also that the Al/Ce/Mg PILC can be used as low cost support for noble-metal-containing active phases.

Synthetic smectites framework substituted with Ti, Fe, and Zn were synthetized in hydrothermal conditions. The materials were characterized by XRD, nitrogen adsorption, MAS-NMR. FT-IR spectroscopy of adsorbed pyridine and analysis of product distribution in the 1-butene isomerization was used to evaluate the surface acidity. Chemical properties were correlated to the nature and presumed lattice location of the framework substituents.