Supported Co catalysts prepared as thin films by magnetron sputtering for sodium borohydride and ammonia borane hydrolysis

Supported Co catalysts were prepared for sodium borohydride and ammonia borane hydrolysis by magnetron sputtering for the first time under different conditions. Ni foam was selected as support. Deposition conditions (time, pressure, and power) were varied to improve catalytic activity. A decrease in deposition power from 200 to 50 W, leads to a decrease in crystallite and column size and a higher activity of catalysts. The increase in deposition pressure from 1.5 × 10−2 to 4.5 × 10−2 mbar produces same effect but in this case the enhancement in activity is higher because amorphous materials were obtained. The highest activity for SB hydrolysis was 2650 ml min−1 gcat−1 for the 50 W Co 4.5 (4 h) sample (Ea = 60 ± 2 kJ mol−1). For AB hydrolysis activity for the 50 W Co 3.2 (4 h) sample was similar. Durability of the thin films was tested for both reactions upon cycling (14 cycles). Diluted acid washing was effective to recover the activity for sodium borohydride reaction but not for ammonia borane hydrolysis. The strong Co–NH3 interactions explain the non-efficiency of the acid washing

Deactivation, reactivation and memoryeffect on Co–B catalyst for sodium borohydride hydrolysis operating in high conversion conditions

9 páginasA system with a continuous reactor to produce hydrogen by sodium borohydride hydrolysis was designed and built. The purpose was to test a supported Co–B catalyst durability upon cycling and long life experiments in high conversion conditions. A Stainless Steel monolith was built and calcined to improve adherence. For comparison a Ru–B catalyst was tested upon cycling. Both Co–B and Ru–B catalysts are durable during 6 cycles and then deactivate. A known reactivation procedure has proven to be more effective for the Co–B than for the Ru–B catalyst. This is related to stronger adsorption of B–O based compounds on the Co–B catalyst which is reversible upon acid washing. For the Ru–B catalyst deactivation may be more related to particle agglomeration than to the adsorption of B–O based species. The continuous system enlarges the catalysts durability because of the continuous borate elimination at elevated temperatures.Financial support from Abengoa Hidrógeno S.A., MICINN (Project CTQ2009-13440), “Junta de Andalucía” (TEP217) and the EC (CT-REGPOT-2011-1-285895, AL-NANOFUNC) is acknowledged. We thank to Dr. Angel Justo for the XRD measurementsPeer reviewe

Nanoscale characterization of Co and Co-B catalytic coatings before and after catalytic tests for the sodium borohydride hydrolysis

Capítulo tomado de https://onlinelibrary.wiley.com/doi/pdf/10.1002/9783527808465.EMC2016.5347Spanish MINECO (CTQ2012-32519 and CTQ2015-65918)CONSOLIDER FUNCOAT+ (MAT2015-69035-REDC)Junta de Andalucía (PE2012-TEP862)CSIC (PIE201460E018)Laboratory for Nanoscopies and Spectroscopies (LANE) at the ICMSTalent-Hub Program funded by the Junta de Andalucía and the European Commission under the Co-funding of the 7thFramework Program in the People Program (Marie Curie Special Action

Pd-C catalytic thin films prepared by magnetron sputtering for the decomposition of formic acid

Formic acid is an advantageous liquid organic hydrogen carrier. It is relatively nontoxic and can be synthesized by the reaction of CO2 with sustainable hydrogen or by biomass decompo-sition. As an alternative to more widely studied powdery catalysts, supported Pd-C catalytic thin films with controlled nanostructure and compositions were newly prepared in this work by mag-netron sputtering on structured supports and tested for the formic acid decomposition reaction. A two-magnetron configuration (carbon and tailored Pd-C targets) was used to achieve a reduction in Pd consumption and high catalyst surface roughness and dispersion by increasing the carbon con-tent. Activity and durability tests were carried out for the gas phase formic acid decomposition reaction on SiC foam monoliths coated with the Pd-C films and the effects of column width, surface roughness and thermal pre-reduction time were investigated. Activity of 5.04 molH2∙gPd−1∙h−1 and 92% selectivity to the dehydrogenation reaction were achieved at 300 °C for the catalyst with a lower column width and higher carbon content and surface roughness. It was also found that deactivation occurs when Pd is sintered due to the elimination of carbon and/or the segregation and agglomera-tion of Pd upon cycling. Magnetron sputtering deposition appears as a promising and scalable route for the one-step preparation of Pd-C catalytic films by overcoming the different deposition characteristics of Pd and C with an appropriate experimental design.Ministerio de Ciencia, Innovación y Universidades RTI2018-093871-B-I0

Deterioro de aleaciones de cobre por acción humana

7 pages, 8 figures. --Technical note.[EN] Results are presented from several samples taken from leaves of the Pardon Portico of Mosque-Cathedral of Cordoba, where an alteration on their surface was detected. Metal samples analyzed using X-ray microanalysis and powder xray diffraction were predominantly constituted by copper with some amounts of zinc attributed to brass, whereas other samples were also constituted by copper, tin and lead attributed to bronze. Surface samples were analyzed using the same techniques. In addition Fourier transform infrared spectroscopy was also used.The main compound identified in all the surface of the leaves is copper chloride hydroxide (atacamite). Lead chlorides have also been found. These data show that the sudden alteration that appears may be attributed to the use of some cleaning product containing chloride. Other compounds detected in the surface were gypsum, quartz and oxalates coming from environmental contamination.[ES] Se exponen los resultados de algunas muestras alteradas procedentes de la Puerta del Perdón, pertenecientes a la Mezquita de Córdoba. Algunas de las muestras de metal analizadas mediante difracción de rayos X y microanálisis por energía dispersiva de rayos X estaban constituidas por latón (cobre con pequeñas cantidades de zinc), mientras que otras estaban constituidas por bronce (cobre, estaño y plomo). La superficie de las muestras se analizó empleando las mismas técnicas. Asimismo, se usó espectroscopia de infrarrojos. El componente principal identificado en la superficie de la puerta es cloruro básico de cobre (atacamita). Además se han encontrado cloruros de plomo. Estos datos demuestran que la repentina alteración de la superficie se puede atribuir al uso de productos de limpieza con alto contenido en cloro. Otros compuestos procedentes de la contaminación externa, como yeso, cuarzo y oxalatos también se detectaron en la superficie.Peer reviewe

Microstructural characterization and thermal stability of He charged amorphous silicon films prepared by magnetron sputtering in helium

Sputtering of silicon in a Helium magnetron discharge has been reported as a bottom-up procedure to obtain amorphous Si films containing high amounts of gas-filled nanopores. Here we compare the microstructure and composition of Si–He nanocomposite films deposited by magnetron sputtering (MS) with 4He in DC or RF and 3He in RF operation modes. Electron microscopy (SEM and TEM), X-ray diffraction (XRD) and ion beam analysis (IBA) have been used to analyze the films and to investigate the in-situ and ex-situ thermal evolution. Depending on deposition conditions different in depth compositions, nanopore size and shape distributions, porosity and He content could be obtained. The presence of impurities (i.e. oxygen) has shown to promote He diffusivity reducing He accumulation. The start temperature of He-release varied in the range 473–723 K without films crystallization. Films grown in RF mode reached contents of 32 and 29 at% of 4He and 3He and were respectively stable up to 573 and 723 K both in vacuum and under inert gas flow. In-situ p-EBS (proton Elastic Back Scattering) allowed monitoring the He release accompanied by blistering/delamination effects visualized by SEM. These results show the potentiality of annealing to hold nano-porous structures after liberation of trapped gas.This work was supported by the Spanish and Junta de Andalucía grants no. RTI2018-093871-BI00, P20-00239 and PID2021-124439NB-I00 (all co-financed by EU FEDER) and the CSIC grant 202160E029.This work was also supported by the region of «Centre Val de Loire» and the European Regional Development Funds (FEDER).Peer reviewe

La Ilustración hispánica. Mestiza y universal

Catálogo de la exposición celebrada en la AECID (Madrid) de septiembre de 2017 a febrero de 2018Antecedentes y precursores de la Ilustración hispánica / Fermín del Pino -- La Escuela Universalista Hispánica o Española del siglo XVIII / Pedro Aullón de Haro -- El Galeón de Manila en la historia de la globalización / Davide Mombelli -- El Pacífico, Filipinas y los Mares del sur / Francisco G. Villanueva -- Expediciones de límites geográficos en América durante la segunda mitad del siglo XVIII / Carmen Martínez Martín -- Andrés, Hervás y la filología universal / Jesús García Gabaldón -- La Ilustración en Filipinas / Isaac Donoso -- La colaboración europea en materia científica. El período ilustrado / Fernando Miguel Pérez Herranz -- La salud como objetivo, la Real Expedición Filantrópica de la Vacuna : textos y contextos / Susana María Ramírez Martín -- El método del viaje / Joaquín Ibáñez Montoya -- La investigación basada en fuentes bibliográficas / Araceli Garcí

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group