Effect of starch as binder in carbon aerogel and carbon xerogel preparation

Carbon aerogels and carbon xerogels were synthesized through resorcinol – formaldehyde polycondensation using Na2CO3 as catalyst. The effect of soluble starch introduction in the organic gel preparation on the porous surface properties of these materials was studied. The role of the drying process of the organic gels on the changes in the surface and structural properties of these materials after the addition of soluble starch is dis- cussed. The presence of starch in the prepared carbon xerogels results in the development of microporosity while maintaining the characteristic mesoporosity of carbon xerogels. The Brunauer – Emmett -Teller (BET) surface area increases from 309 m2/g in carbon xerogel without soluble starch until 685 m2/g when 10% of soluble starch is added. The R- value and average crystallite lattice parameters, inter-layer spacing, crystallite height, crystallite diameter and the average number of aromatic layers per carbon crystallite are discussed in function of drying step and presence of soluble starch. The surface properties were also studied by Raman and DRIFT spectroscopiesMinisterio de Educación y Competitividad de España (MINECO) y Fondos FEDER de la Unión Europea-ENE2013-47880-C3-2-R y ENE2017-82451-C3-3-

Policies and Motivations for the CO2 Valorization through the Sabatier Reaction Using Structured Catalysts. A Review of the Most Recent Advances

The current scenario where the effects of global warming are more and more evident, has motivated different initiatives for facing this, such as the creation of global policies with a clear environmental guideline. Within these policies, the control of Greenhouse Gase (GHG) emissions has been defined as mandatory, but for carrying out this, a smart strategy is proposed. This is the application of a circular economy model, which seeks to minimize the generation of waste and maximize the efficient use of resources. From this point of view, CO2 recycling is an alternative to reduce emissions to the atmosphere, and we need to look for new business models which valorization this compound which now must be considered as a renewable carbon source. This has renewed the interest in known processes for the chemical transformation of CO2 but that have not been applied at industrial level because they do not offer evident profitability. For example, the methane produced in the Sabatier reaction has a great potential for application, but this depends on the existence of a sustainable supply of hydrogen and a greater efficiency during the process that allows maximizing energy efficiency and thermal control to maximize the methane yield. Regarding energy efficiency and thermal control of the process, the use of structured reactors is an appropriate strategy. The evolution of new technologies, such as 3D printing, and the consolidation of knowledge in the structing of catalysts has enabled the use of these reactors to develop a wide range of possibilities in the field. In this sense, the present review presents a brief description of the main policies that have motivated the transition to a circular economy model and within this, to CO2 recycling. This allows understanding, why efforts are being focused on the development of different reactions for CO2 valorization. Special attention to the case of the Sabatier reaction and in the application of structured reactors for such process is paid

CO oxidation at low temperature on Au/CePO4: Mechanistic aspects

This work reports the synthesis and characterization of a cerium phosphate supported gold catalyst as well as its catalytic activity for the oxidation of CO. A precipitation method in the presence of an organic modifier followed by a hydrothermal treatment was used for the support synthesis, resulting in high surface area nanometric particles. Gold/cerium phosphate catalyst with a 1% (w/w) nominal gold content was characterized using XRF, XRD, N2 adsorption-desorption measurements, TEM and DRIFTS-MS. The catalyst shows good catalytic activity at low temperature. The activity is related to the generation of oxygen vacancies in the support caused by the elimination of structural oxygen. In situ studies revealed that the reaction of the oxygen vacancies with gaseous oxygen resulted in the formation of peroxo species. These species are responsible for the activity detected at room temperature in both the catalyst and the support. Moreover, the presence of carbonate and hydrogen carbonate acting as reaction intermediates have been observed

Recycling of construction and demolition waste generated by building infrastructure for the production of glassy materials

The use of waste materials generated by construction and demolition industry to yield valuable glassy materials, i.e. enamel for glazed ceramic tiles and cellular glasses is presented in this study. Both types of materials are produced by one-step treatment at moderate temperatures after simple waste chemical composition adjust. The enamels are manufactured directly from the initial waste powder by melting, while the expanded materials result from mixing of the vitreous material obtained after waste vitrification with an adequate foaming agent and posterior thermal treatment. Through the manuscript the feasibility of one step production of second generation profit materials is discussed in order to help achieving sustainable development and environmental protectio

Low-temperature CO oxidation on multicomponent gold based catalysts

In this work the development of gold catalysts, essentially based on ¿-alumina with small superficial fraction of Ce-Fe mixed oxides as support for the low temperature CO oxidation is proposed. Characterization results obtained by means of TEM, OSC, XPS, UV-Vis spectroscopy and H2-TPR are employed to correlate the activity data with the catalysts composition. The bare ¿-alumina supported gold catalyst demonstrates the poorest activity within the series. The addition of CeO2 or FeOX improves the catalytic performance, especially observed for the CeO2-FeOx mixed oxide doped samples. This enhanced CO oxidation activity was related to the Ce-Fe interaction producing materials with promoted redox properties and therefore oxidation activity.Peer Reviewe

Giant cell arteritis: is the clinical spectrum of the disease changing?

Background: Giant cell arteritis is a vasculitis of large and middle-sized arteries that affects patients aged over 50 years. It can show a typical clinical picture consisting of cranial manifestations but sometimes nonspecific symptoms and large-vessel involvement prevail. Prompt diagnosis and treatment is essential to avoid irreversible damage. Discussion: There has been an increasing knowledge on the occurrence of the disease without the typical cranial symptoms and its close relationship and overlap with polymyalgia rheumatica, and this may contribute to reduce the number of underdiagnosed patients. Although temporal artery biopsy is still the gold-standard and temporal artery ultrasonography is being widely used, newer imaging techniques (FDG-PET/TAC, MRI, CT) can be of valuable help to identify giant cell arteritis, in particular in those cases with a predominance of extracranial large-vessel manifestations. Conclusions: Giant cell arteritis is a more heterogeneous condition than previously thought. Awareness of all the potential clinical manifestations and judicious use of diagnostic tests may be an aid to avoid delayed detection and consequently ominous complications.This review was funded by Roche Farma S.A. Spain

Low temperature CO oxidation

Catalytic low-temperature abatement of carbon monoxide becomes essential in environmental pollution control. CO Oxidation, CO Preferential Oxidation (PROX) and Water Gas Shift (WGS) reaction are the conventional technologies used to remove carbon monoxide at low temperature. Perovskite-type oxides have been extensively studied in the last years as catalysts for these reactions due to their high activity and catalytic stability. This chapter describes the state-of-the-art of using perovskite-based catalysts of general formula ABO3 in these reactions. Key factors such as the type and nature of A and B ions or the formation of oxygen vacancies or interstitials by doping are discussed in the light of the reaction mechanism in each casePeer reviewe

Ru–Ni Catalyst in the Combined Dry-Steam Reforming of Methane: The Importance in the Metal Order Addition

Biogas is one of the main biomass-energy resources. Its use for syngas production with a H2/CO ratio close to two would have huge environmental, social and economic impact in the actual energetic scenario. However, the use of dry reforming, where the two main components are transformed into syngas, does not allow the desired H2/CO ratio. For this reason, the addition of water is proposed. The process was performed with two Ru–Ni catalysts where the metal order in the impregnation process was varied. The catalysts were prepared either by simultaneous or consecutive impregnation of the active phases and its catalytic performance in the combined dry-steam reforming of methane was tested. The catalysts were characterized by XRF, XRD, SBET, TPR-H2 and Raman spectroscopy. The existence of a strong Ni–Ru interaction is evidenced by Raman spectroscopy and TPR-H2 in the sample synthesized by the simultaneous impregnation. Concerning the catalytic activity, this sample presents the highest CH4 and CO2 conversion values in the entire composition rate and the lowest amount of carbon deposits after reaction. After pulse, and reactivity tests it was concluded that the higher Ni–Ru interaction displayed by the catalyst synthesized by the simultaneous impregnation, enhances the carbon gasification.España Mineco ENE2012-374301-C03-01 ENE2013-47880-C3-2-RJunta de Andalucía FEDER TEP-819

Aula Invertida en la Ingeniería del Terreno Asistida por Ordenador [Flipped Classroom in Computer-Aided Ground Engineering]

Para superar las limitaciones de la metodología tradicional en la enseñanza de AutoCAD, la Unidad Docente de Expresión Gráfica de la Universidad Politécnica de Madrid está llevando a cabo un Proyecto de Innovación Educativa para implementar una metodología de Aula Invertida (AI) con el apoyo de vídeos educativos. En este trabajo se presentan los resultados de una primera aplicación práctica de la metodología de AI llevada a cabo durante el curso 2016/2017 sobre el tema “La impresión en AutoCAD”. La aplicación de la metodología ha incluido el empleo de un grupo de control y la realización de una prueba objetiva sobre el uso de AutoCAD, la cual ha supuesto un reto organizativo para la Unidad Docente. Los resultados del estudio muestran un mejor rendimiento de los alumnos que han empleado AI. Sin embargo, esta mejora no parece deberse directamente al AI como técnica de enseñanza sino a su aspecto motivador que incide de manera general en el rendimiento de los alumnos. [In order to overcome the limitations of traditional teaching methodologies in AutoCAD classes, the Graphic Expression Teaching Unit of the Technical University of Madrid is carrying out an Innovative Teaching Project to implement a Flipped Classroom (FC) methodology with the support of educational videos. This paper presents the results of a first application of the FC methodology carried out during the academic year 2016/2017 on the topic of “Printing in AutoCAD”. The application of the methodology involved a control group and an exam on the use of AutoCAD, all of which has been an organizational challenge for the Teaching Unit. The results of the study show an improved performance by the students who used FC. However, this improvement does not seem to be due directly to FC as a teaching technique, but rather to its motivating character, which has a general impact on student performance.