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In this study, we assessed the effect of the incorporation of multi-walled carbon nanotubes (MWCNT) on a TiO2 support containing different active metals to obtain Metal/TiO2-MWCNT photocatalytic systems. The materials prepared in this work were characterized by ICP-OES, TEM, EDX, XRD, PL, UV–vis, and nitrogen physisorption techniques. Among those investigated metals, Cu was shown to be the most promising for the present application. The assessment of the photocatalytic performance of Cu/TiO2-MWCNT with various Cu contents revealed that the catalytic activity depends on the Cu loading and the photocatalyst with 1 wt.% of Cu displayed the best performance among investigated. The incorporation of MWCNT in the support enhanced the photocatalytic activity towards the production of H2 under visible and UV–vis light irradiation at room temperature. The authors thank Ministerio de Ciencia Innovación y Universidades and FEDER (Project RTI2018-095291-B-I00) and the Generalitat Valenciana (PROMETEOII/2018/076) for financial support. JFC thanks MINECO for a researcher formation grant (BES-2016-078079). MNG gratefully acknowledges Generalitat Valenciana and Plan GenT (CDEIGENT/2018/027) for the postdoctoral grant. The present work was partially supported by Grants-in-Aid for Scientific Research (Nos. 26220911, 19H00838) from the Japan Society for the Promotion of Science (JSPS) and MEXT. KM, YK, and HY thank MEXT program “Elements Strategy Initiative to Form Core Research Center.

Palladium nanoparticles protected by polyvinylpyrrolidone (PVP) have been synthesized by the reduction-by-solvent method and deposited onto alumina by the wet impregnation method. The metallic colloid has been left for different times (aging times) at room temperature and under open bench conditions before deposition of the particles on the support. The colloids have been analyzed by TEM, and the catalysts prepared have been characterized by TEM, TG-MS, XPS and IR spectroscopy. The catalytic activity of the nanoparticles has been tested in the preferential oxidation (PrOx) of CO reaction, which consists in CO removal from H 2 -rich streams. The reaction was conducted up to 200 °C and with a gas composition similar to that coming out from a reformer (2% CO, 2% O 2 , 30% H 2 , He). The aging time of the colloidal suspensions, i.e. the time elapsed between colloids preparation and deposition, does not have an influence over the nanoparticles size or shape. However, this parameter has shown a great influence on the catalytic behavior of the metal nanoparticles, affecting both their catalytic activity and selectivity. The catalyst impregnated with the immediately prepared nanoparticles is the one showing the best catalytic properties in this work. The amount of polymer anchored to the particles surface and its interaction with the metal surface has been found to be responsible for these observations.

In this work, the oxidative dehydrogenation (ODH) of ethylbenzene to styrene reaction over an activated carbon felt was studied by experiments of mass spectrometry coupled to a quasi in situ XPS system. These experiments permit to deepen into the mechanism of the aforementioned reaction. The results obtained allow us to conclude that carbonyl-quinone and hydroxyl groups are involved in the ODH. The amount of both types of oxygen groups increases when the ethylbenzene conversion to styrene increases. Therefore, the reaction seems to take place through the carbonyl-quinone/hydroxyl and styrene/ethylbenzene redox couples, confirming that carbonyl-quinone are the active phase in this oxidative dehydrogenation.

Fil: de Miguel, Sergio Ruben. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe. Instituto de Investigaciones en Catalisis y Petroquimica "Ing. Jose Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catalisis y Petroquimica "Ing. Jose Miguel Parera"; Argentina

Various “in situ” techniques, including thermogravimetry (TG), differential thermal analysis (DTA), isothermal chemisorption, temperature-programmed desorption (TPD), intermittent TPD, temperature programmed reaction (TPR) and BET surface area determination, have been used to characterize calcium as a catalyst of carbon gasification. These techniques were first established with pure CaO samples and then applied to the CaO-carbon system. These methods, and particularly TPD accompanied by internal sample gasification, proved to be an efficient means of getting new insights into the calcium-catalyzed carbon gasification.