Bimetallic Pt-Pd co-catalyst Nb-doped TiO2 materials for H2 photo-production under UV and Visible light illumination

In this work we synthesized a series of binary PtPd co-catalysts supported on a Nb-doped TiO2 support. The catalytic solids and corresponding monometallic reference systems are characterized using X-ray diffraction, X-ray photoelectron, and UV–vis spectroscopies, together with microscopy and porosimetry tools. Such characterization was able to show the formation of PtPd alloy particles in the bimetallic catalysts. The mono and bimetallic TiO2-based powders were tested in the photo-production of hydrogen from methanol:water mixtures under UV and visible illumination conditions. Analysis of catalytic properties was carried out through the measurement of the optical properties of the materials and the calculation of the true quantum efficiency parameter. Results indicate that the PtPd co-catalysts have superior performance that the Pt and Pd monometallic counterparts both under UV and visible illumination conditions. Optimum performance was achieved with a material having a Pt:Pd 1:1 atomic ratio. A remarkable increase in the use of the visible range and thus in sunlight utilization is achieved with the 1:1 Pt:Pd bimetallic system with respect to the monometallic counterparts. The evolution of the bimetallic co-catalysts under reaction conditions as well as their key properties to interpret photo-activity were analyzed with the help of the above mentioned techniques as well as photoluminescence spectroscopy and an in-situ infrared analysis of the materials under reaction conditions. Results point out the critical role that both PtPd alloying and the metal-support interface play in the reaction

Recent progress in the quantitative assessment and interpretation of photoactivity

The development of the photo-catalysis field is limited by a deficient quantitative assessment of photo-activity. The interplay between mass and momentum transport together with radiative transfer phenomena taking place at any photo-catalytic reaction or process makes complex such quantitative assessment. To reach this goal, the review studies the measurement, meaning, and analysis of three types of observables. The first family of observables has the reaction rate and closely connected observables as the turnover frequency as central pieces. The second family owns the so-called efficiency observables, starting from the photonic yield and quantum efficiency of the reaction and ending in the global efficiency of the process. Finally, the review studies kinetic constant observables. The contribution focusses on most rencet contribution analyzing these observables in terms of their (adequate) measurement conditions and physico-chemical interpretation, in order to unveil their full potential in the context of the photo-catalysis field.MCIN/AEI PID2019-105490RB-C31ERDF A way of making EuropeEuropean CommissionConsejo Nacional de Ciencia y Tecnologia (CONACyT) SENER-CONACyT 117373UGR PPJIA2019-0

Role of alkali-cyano group interaction in g-C3N4 based catalysts for hydrogen photo-production

Carbon nitride based materials incorporating K and Na alkali ions were used as support(s) to deposit platinum. The systems were tested in the photo-production of hydrogen using methanol as a sacrificial molecule. Tests under UV and sunlight-type illumination conditions showed an important promoting effect of the alkali ions irrespective of the illumination source characteristics. The measurement of the quantum efficiency was used to quantitatively assess the performance of the catalysts. Outstanding results were obtained, particularly under sunlight illumination. A complete characterization study of the materials was carried out to establish a structure-activity link. This link correlates catalytic activity with the capture of charge carrier species by surface cyano groups directly associated with the presence of alkali ions at the carbon nitride componen

DISEÑO Y CONSTRUCCIÓN DE UNA ESTACIÓN DE CONFORMADO DE SOLERA

En éste trabajo se presenta el diseño y fabricación de un sistema de conformado de un material compuesto o solera de dos materiales empleada en distintas aplicaciones de la industria metalmecánica. El diseño de la estación de conformado se divide en dos partes: una estación de rolado y una estación de doblado. Para el desarrollo del sistema se emplearon las especificaciones de la solera, y con estas desarrollar un prototipo conceptual, el cual ayudó a conocer los parámetros principales a considerar en el diseño y fabricación de las estaciones de formado. Finalmente se presenta el sistema de conformado automático con intervención mínima del operador. Palabra(s) Clave(s): Diseño mecánico, solera, conformado, rolado, doblad

Facile synthesis of B/g-C3N4 composite materials for the continuous-flow selective photo-production of acetone

In this work versatile boron–carbon nitride composite materials were synthesized and utilized in a sustainable process using sunlight as the energy source for the continuous-flow selective photocatalytic production of acetone from 2-propanol. It is worth highlighting that the sample preparation was carried out by an environmentally friendly strategy, without a solvent or additional reagents. Samples containing boron in 1–10 wt% were subjected to physico-chemical characterization using XRD, porosimetry, UVvisible spectroscopy, TEM, energy-dispersive X-ray spectroscopy and XPS. The reaction output was analyzed on the basis of the reaction rate, selectivity and quantum efficiency of the process. A correlation analysis between catalytic properties with two observables, the boron phase distribution in the materials and charge handling efficiency (measured using photoluminescence), rationalizes photoactivity. Such an analysis indicates that the presence of an amorphous boron metallic phase and its contact with the carbon nitride component are key to setting up a renewable and easily scalable chemical process to obtain acetone.MINECO (Spain) ENE2016-77798-C4-1-RConsejo Superior de Investigaciones Cientificas (CSIC)Secretaria de Ciencia Tecnologia e Innovacion of CDMX (SECTEI, Mexico)MINECO CTQ2016-78289-PEuropean Union (EU)RUDN University Program 5-10

The trans fatty acid elaidate affects the global DNA methylation profile of cultured cells and in vivo

BACKGROUND: The deleterious effects of dietary trans fatty acids (tFAs) on human health are well documented. Although significantly reduced or banned in various countries, tFAs may trigger long-term responses that would represent a valid human health concern, particularly if tFAs alter the epigenome. METHODS: Based on these considerations, we asked whether the tFA elaidic acid (EA; tC18:1) has any effects on global DNA methylation and the transcriptome in cultured human THP-1 monocytes, and whether the progeny of EA-supplemented dams during either pregnancy or lactation in mice (n = 20 per group) show any epigenetic change after exposure. RESULTS: EA induced a biphasic effect on global DNA methylation in THP-1 cells, i.e. hypermethylation in the 1–50 μM concentration range, followed by hypomethylation up to the 200 μM dose. On the other hand, the cis isomer oleic acid (OA), a fatty acid with documented beneficial effects on human health, exerted a distinct response, i.e. its effects were weaker and only partially overlapping with EA’s. The maximal differential response between EA and OA was observed at the 50 μM dose. Array expression data revealed that EA induced a pro-inflammatory and adipogenic transcriptional profile compared with OA, although with modest effects on selected (n = 9) gene promoter methylation. In mice, maternal EA supplementation in utero or via the breastmilk induced global adipose tissue DNA hypermethylation in the progeny, that was detectable postnatally at the age of 3 months. CONCLUSION: We document that global DNA hypermethylation is a specific and consistent response to EA in cell culture and in mice, and that EA may exert long-term effects on the epigenome following maternal exposure. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12944-016-0243-2) contains supplementary material, which is available to authorized users

Associations between whole peripheral blood fatty acids and DNA methylation in humans

Fatty acids (FA) modify DNA methylation in vitro, but limited information is available on whether corresponding associations exist in vivo and reflect any short-term effect of the diet. Associations between global DNA methylation and FAs were sought in blood from lactating infants (LI; n = 49) and adult males (AMM; n = 12) equally distributed across the three conventional BMI classes. AMM provided multiple samples at 2-hour intervals during 8 hours after either a single Western diet-representative meal (post-prandial samples) or no meal (fasting samples). Lipid/glucose profile, HDAC4 promoter and PDK4 5'UTR methylation were determined in AMM. Multiple regression analysis revealed that global (in LI) and both global and PDK4-specific DNA methylation (in AMM) were positively associated with eicosapentaenoic and arachidonic acid. HDAC4 methylation was inversely associated with arachidonic acid post-prandially in AMM. Global DNA methylation did not show any defined within-day pattern that would suggest a short-term response to the diet. Nonetheless, global DNA methylation was higher in normal weight subjects both post-prandially and in fasting and coincided with higher polyunsaturated relative to monounsaturated and saturated FAs. We show for the first time strong associations of DNA methylation with specific FAs in two human cohorts of distinct age, diet and postnatal development stage

Thermo-photo production of hydrogen using ternary Pt-CeO2-TiO2 catalysts: A spectroscopic and mechanistic study

Authors are thankful to “Ministerio de Ciencia, Innovaci´on y Universidades” (Spain) for supporting the work carried out through the PID2019-105490RB-C31 grant. ESRF (BM23 beamline) synchrotron and staff (Drs. G. Agostini and O. Mathon) are also thanked for the provision of beamtime as well as the supply of reference materials/spectra. The support by CONACyT, Mexico (SENER-CONACyT 117373) is also acknowledged by U. C.-F. I. B.-N. thanks MINECO for a FPI doctoral fellowship (BES-2017-080069). MF-G acknowledges Prof. F. Fern´andez- Martín for fruitful discussions.The gas phase thermo-photo production of hydrogen from methanol:water mixtures was tested using platinum ceria-titania ternary solids. This contribution focusses on the analysis of the role of ceria and the usefulness of combining heat and light sources in order to boost catalytic activity. To this end, we provide a quantitative assessment of thermo-photo activity as well as a detailed characterization of the catalytic solids with emphasis in the use of in-situ X-ray absorption and infrared spectroscopies. The adequate combination of components in the platinum ceria-titania ternary system renders highly active and stable catalysts, maximizing hydrogen production (rate of ca. 45 mmol g-1h−1) for a solid having a 1/2.5 wt% of platinum/ceria supported on titania. The characterization shows that this occurs through a synergetic effect among components of the solids and takes place with a critical role of defects located at the ceria-titania interface and the noble metal component. The cooperative action between components promotes the evolution of specific carbon-containing intermediates (related to the step-wise hole-triggered oxidation of the methanol molecule, decarbonylation of intermediates and the water gas shift) and the concomitant production of hydrogen.“Ministerio de Ciencia, Innovación y Universidades” (Spain) (PID2019-105490RB-C31 grant. ESRF (BM23 beamline)CONACyT, Mexico (SENER-CONACyT 117373)MINECO (BES-2017-080069

SCIPP: An Expanded Community of Practice - Community Publishing

SCIPP redefines and expands the existing notions about what makes for a vibrant and robust community of practice by partnering CSUSB students and professors with K-12 students, parents, and educators, along with committed community partners. SCIPP encourages curiosity in ways that leads to critical thinking, exploration, risk taking , confidence building, open-mindedness, and other personal traits that equip them with the softskills to be active, critical, and creative contributors to our communities. SCIPP pedagogy embraces our students\u27 collective wisdom and focuses on relational building where multi-directional communication is promoted and students are viewed as equal stakeholders in their own educations. SCIPP puts collaboration into action which in turn fosters community-based lifelong learning. SCIPP provides the open intellectual space for future university students (our K-12 students) to engage with existing university students in meaningful ways so as to sustain interconnected partnerships facilitating community engagement. It supports parents as experts in the education of their children and acknowledges parents as the first conduits to spark their children’s imagination while they actively participate in education enriching activities and programs. Everyone involved is committed to creating a secure and open atmosphere for dreaming, sharing, and learning. Together we explore the aspects of community publishing through collaborative learning in formal and informal settings relating to digital and printed medias