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In this work different variables that can affect the catalytic behavior of CuO-CeO2 supported on mesoporous silica (SBA-15 and SBA-16) were studied. The influence on the COPrOx activity of the relative concentration of the CuO and CeO2 active phase and different impregnation methods in mesoporous support was analyzed. The physicochemical characterization was performed EDS-SEM and TEM-STEM, N2 isotherms, X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). The incipient wetness impregnation method (IWI) was the better alternative to introduce the active phases compared to solid state impregnation (SSI). In addition, the catalysts based on 2-D structure of SBA-15 were more active and selective than those based in 3-D SBA-16. In general, the high surface area of the supports benefited the dispersion of CuO and CeO2 oxides nanoparticles. All catalysts displayed the preservation of the mesostructure and the formation of nanoparticles of active phases (less than 10 nm) detected by TEM. The best COPrOx catalyst, obtained from the SBA-15 fibers by IWI method, with a relative CuO concentration of 0.2, exhibited XCO ≥ 99% at 175 °C and above 90% in a wide window of temperatures. This catalyst showed an adequate performance in presence of CO2 and H2O and good recovery of CO conversion and selectivity. The analysis by XPS revealed that the majority species were Ce4+, however in some catalysts Ce3+ species are also present, which are associated with vacancies oxygen and favor the redox process. In addition, Cu2+ and Cu+ species are present, the latter recognized as a key site of CO adsorption in the reaction mechanism.

Powder and structured catalysts based on CuO–CeO2 nanoparticles dispersed on different silica are studied in CO preferential oxidation. Silica of natural origin (Celite) and fumed silica (aerosil), both commercial materials, and synthesized mesoporous SBA-15 with 20, 200 and 650 m2g-1 respectively, are selected as supports. CuCe/Celite coated on cordierite monolith displays the highest activity, reaching CO conversion above 90% between 140 and 210 °C and more than 99% around 160 °C. The addition of 10% CO2 and 10% H2O partially deactivates the monolithic catalyst. The lower surface area of CuCe/Celite favors the contact between CuO and CeO2 nanoparticles promoting a better interaction of Cu+2/Cu+ and Ce+3/Ce+4 redox couples. Raman spectroscopy reveals oxygen vacancies and XPS results show high metal lattice surface oxygen concentration and surface enrichment of Cu and Ce which promote the catalytic activity.

International audience; In the present work, SBA-15 and SBA-16 ordered mesoporous silicas were synthesized with different morphologies such as fibers, spheres, rods and irregular shapes. Copper and cerium oxides active phase was introduced by two methods, incipient wetness impregnation and solid-state impregnation by using a ball mill. The obtained catalysts were evaluated in the CO preferential oxidation reaction (COPrOx). By means of SAXS, XRD, SEM and TEM microscopies, the mesostructures and morphologies were characterized, as well as the preservation of the porous structure and the presence of oxides nanoparticles. In addition, XPS spectroscopy was used to analyze the chemical state and relative surface abundance of the elements present in the catalysts. From the catalytic results, it could be seen that the incipient wetness impregnation method was the most favorable. The unidirectional porous structure SBA-15 with fiber shape and incipient wetness impregnation achieved the highest conversion of CO and selectivity to CO2 (CO conversion 98% at 175 °C). SBA-16 based catalysts were found less active. However, it is noteworthy that the best material was prepared by using an irregular shaped SBA-16 impregnated by incipient wetness procedure. This catalyst exhibited a maximum CO conversion of 80% at 175 °C. Finally, the SBA-15 mesoporous structure and the incipient wetness impregnation method had a greater influence on the better catalytic performance.

CuO-CeO2/SBA-15 catalysts deposited over cordierite monoliths were prepared to be tested in CO preferential oxidation (COPrOx). The influence of molar ratio between the CuO and CeO2 active phases, their concentration, and the incorporation method into the mesoporous structure were analyzed. Powder catalysts were also studied in order to select the best formulations to coat the monolith walls. Four CuO/CeO2 molar ratios over SBA-15 were obtained by incipient wetness impregnation technique (successive impregnation and co-impregnation). The CuO/CeO2 = 0.55 ratio powder catalyst showed the best CO conversion in the temperature range studied, reaching 100% at 160 °C. The incorporation of active phases into the structured support produced similar or better catalytic behaviors. The addition of 10% CO2 slightly decreased the CO conversion, while the addition of 10% H2O partially deactivated the catalyst. The structured and powder catalysts prepared were characterized by N2 sorption, TEM, SEM, XRD, XPS and TPR in order to identify and relate their physico-chemical properties with the catalytic behavior. Fil: Lacoste, Albano Mauricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentina Fil: Tiscornia, Ines Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentina Fil: Boix, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentina

A multidisciplinary non-destructive study has been carried out on historical pipe organ fragments, trying to infer whether the spatial occurrence of different crystallographic phases (that is alpha-tin, beta-tin, cassiterite or romarchite) reflects the visible alterations patterns. We could indeed derive the presence of the beta-tin phase. Several tin oxide phases have been detected too, associated with the visible occurrence of “grey regions” and hole borders (mapped by Raman spectroscopy), and hydrate phases (mapped by neutron imaging). We aim to demonstrate that neutron and Raman techniques can give relevant indications in archaeometallurgy studies of cultural heritage artifacts, where only non-destructive experiments can be performed. The combination of the two probes could be considered a protocol to be applied in the characterization of tin based specimens.

In this study, we tested the “land-subsidence monitoring guidelines” proposed by the Italian Ministry of Economic Development (MISE), to study ground deformations along on-shore hydrocarbon reservoirs. We propose protocols that include the joint use of Global Positioning System (GPS) and multi-temporal Differential Interferometric Synthetic Aperture Radar (DInSAR) techniques, for a twofold purpose: a) monitoring land subsidence phenomena along selected areas after defining the background of ground deformations; b) analyzing possible relationships between hydrocarbon exploitation and anomalous deformation patterns. Experimental results, gathered along the Ravenna coastline (northern Italy) and in the southeastern Sicily (southern Italy), show wide areas of subsidence mainly related to natural and anthropogenic processes. Moreover, ground deformations retrieved through multi-temporal DInSAR time series exhibit low sensitivity as well as poor spatial and temporal correlation with hydrocarbon exploitation activities. Results allow evaluating the advantages and limitations of proposed protocols, to improve the techniques and security standards established by MISE guidelines for monitoring on-shore hydrocarbon reservoirs.

Historic musical instruments, especially violins, have witnessed centuries of stories and events, passing from hand to hand among musicians, collectors and restorers. Historical last wills and trading documents makes it possible to reconstruct the movements around the world of the decorated ex-San Lorenzo violin and its story throughout its owners. The history of this precious violin began in 1718 in the Cremonese workshop of Antonio Stradivari. It represents a mature example of the Master's “Golden Age” period (1700 to 1720) and is unique for an unusual inscription “GLORIA ET DIVITIAE IN DOMO EIUS” which adorns its center-bout ribs. Numerous imaging techniques (stereomicroscopy, optical microscopy, VIS and UV photography, X-ray radiography, XRF mapping), spectroscopic (FORS, FTIR in reflectance mode, XRF, SEM-EDX) and chromatographic (Pyrolysis SolidPhase Microextraction Gas Chromatography-Mass spectrometry) were applied in order to: (i) give new data related to both original and restoration materials, (ii) make considerations about the restoration procedures adopted over the centuries, and (iii) highlight the main issues of historic musical instrument preservation. The material information gathered from this multi-technique study is varied depending on the areas under investigation. This analytical campaign, which is the widest ever made on a single musical instrument, gives a new overview of the materials applied on historic bowed musical instruments and opens debate about what should be preserved and how to do it.

Seismotectonic activity and slope instability are a permanent threat in the archaeological site of Abakainon and in the nearby village of Tripi in NE Sicily. In recent times, signs of an ancient earthquake have been identified in the necropolis of Abakainon which dating was ascertained to the first century AD earthquake. The site is located on a slope of Peloritani Mts. along the Tindari Fault Line and contains evidence for earthquake-induced landslide, including fallen columns and blocks, horizontal shift and counter slope tilting of the tomb basements. In this paper, we used an integrated geomorphological and geophysical analysis to constrain the landslide. The research was directed to the acquisition of deep geological data for the reconstruction of slope process and the thickness of mobilized materials. The applied geophysical techniques included seismic refraction tomography and electrical resistivity tomography. The surveys were performed to delineate the sliding surface and to assess approximately the thickness of mobilized materials. The geophysical and geomorphologic data confirmed the presence of different overlapped landslides in the studied area. Moreover, a numerical simulation of the slope under seismic loads supports the hypothesis of a mobilization of the landslide mass in case of strong earthquakes (PGA > 0.3 g). However, numerical results highlight that the main cause of destruction for the Abakainon necropolis is the amplification of the seismic waves, occasionally accompanied by surficial sliding.