Search

Your search keyword '"Calvino, José J."' showing total 35 results
Start Over Author "Calvino, José J." Publication Year Range Last 3 years
35 results on '"Calvino, José J."'

1. Ultrathin Washcoat and Very Low Loading Monolithic Catalyst with Outstanding Activity and Stability in Dry Reforming of Methane

Author

Agueniou, Fazia, Vidal, Hilario, Yeste, Maria Pilar, Hernandez-Garrido, Juan C., Cauqui, Miguel A., Rodriguez-Izquierdo, Jose M., Calvino, Jose J., and Gatica, Jose M.

Subjects
Condensed Matter - Materials Science
Abstract

A Ni/CeO2/ZrO2 catalyst with improved redox properties has been washcoated onto a honeycomb cordierite monolith in the form of a nonconventional alumina-catalyst layer, just a few nanometer thick. In spite of the very low active phase loading, the monolith depicts outstanding performance in dry reforming of methane, both in terms of activity, with values reaching the thermodynamic limit already at 750 C, even under extreme weight Hourly Space Velocities (WHSV 115-346 L.g-1.h-1), as well as in terms of stability during prolonged time on stream (TOS 24-48 h)., Comment: 7 pages, 3 figures, 19 references. Gold Open Access

Published
2024
Full Text
View/download PDF

2. An atomically efficient, highly stable and redox active Ce0.5Tb0.5Ox (3% mol.)/MgO catalyst for total oxidation of methane

Author

Sanchez, Juan J., Lopez-Haro, Miguel, Hernandez-Garrido, Juan C., Blanco, Ginesa, Cauqui, Miguel A., Rodríguez-Izquierdo, Jose M., Perez-Omil, Jose A., Calvino, Jose J., and Yeste, Maria P.

Subjects
Condensed Matter - Materials Science
Abstract

Redox and catalytic performance in total methane oxidation of a nonostructured ceria-terbia catalyst supported on magnesia is presented and compared to that of a pure ceria catalyst supported on MgO. The investigated material, Ce0.5Tb0.5Ox (3% mol.)/MgO, features several remarkable properties: a quite low total molar loading of the two lanthanide elements, high reducibility, as well as very high oxygen storage capacity al low temperatures and higher activity than MgO-supported ceria. In terms of lanthanide atomic content the catalytic performance of Ce0.5Tb0.5Ox (3% mol.)/MgO largely improves compared to that of bulk type ceria and ceria-magnesia solid solutions. Such a behavior implies proper optimization of the usage of lanthanide elements. A second contribution to atomic economy in the catalyst design relates to the fact that the new formulation demonstrate a stabilyty in the redox and catalytic performance against very high temperature treatments. An investigation on the structure of both the fresh and high-temperature-aged catalyst at the atomic scale by means of complementary aberration corrected microscopy techniques, reveals the ocuurrence of a variety of exotic, lanthanide-containing nanostructures, which span fron isolated, atomically dispersed Ln species to nonometer-sized CeTbO2-x patches, extended CeTbO2-x bilayers and 2D CeTbO2-x nanoparticles. Nanoanalytical results evidence the mixing of the two lanthanides at atomic levels in these nanostructures. The combined effects of nanostructuring, mixing of the lanthanides at the atomic level, and interaction with the MgO oxide are the roots of the improvement in funtional, redox and catalytic properties of the novel Ce0.5Tb0.5Ox (3% mol.)/MgO catalyst., Comment: 11 pages, eight figures, 3 tables, 60 references

Published
2024
Full Text
View/download PDF

3. Honeycomb monolithic design to enhance the performance of Ni-based catalysts for dry reforming of methane

Author

Agueniou, Fazia, Vidal, Hilario, Yeste, M. Pilar, Hernandez-Garrido, Juan C., Cauqui, Miguel A., Rodriguez-Izquierdo, Jose M., Calvino, Jose J., and Gatica, Jose M.

Subjects
Condensed Matter - Materials Science
Abstract

Supported Ni catalysts (4,5% wt%) using a Ce-Zr oxide (18/82 molar ratio and a ceria rich surface) depicting advanced redox properties, were deposited by washcoating over cordierite honeycombs (230 and 400 cpsi). FIB-STEM unveiled nanostructure details otherwise undistinguishable by conventional techniques. The catalytic performance was evaluated in the dry reforming of methane al 700-900 degree C, using a CH4:CO2 1:1 feddstock, and exploring high Weight Hourly Space Velocity (115-346 L.g-1.h-1). The structured catalyts exhibited better performance than the corresponding powers, reaching values close to rhermodynamics limits for booth reactants conversion and H2/CO ratio, from 750 dgree C, and no deactivation was observed in prolongued experiments (24-48 h). This was related to both the high catalytic efficiency after being deposited with low loading on the cordierite and the intrinsic advantages of the monolithic reactor, like preventing from the kinetic control that operates in powdered samples under high WHSV or limiting the deactivation., Comment: 10 pages, 8 figures, 3 tables, 61 references

Published
2024
Full Text
View/download PDF

12. Multicationic Sr4Mn3O10 mesostructures: molten salt synthesis, analytical electron microscopy study and reactivity

Author

González-Jiménez, Irma N., Torres-Pardo, Almudena, Rano, Simon, Laberty-Robert, Christel, Hernández-Garrido, Juan carlos, López-Haro, Miguel, Calvino, José J., Varela, Áurea, Sanchez, Clément, Parras, Marina, González-Calbet, José M., Portehault, David, González-Jiménez, Irma N., Torres-Pardo, Almudena, Rano, Simon, Laberty-Robert, Christel, Hernández-Garrido, Juan carlos, López-Haro, Miguel, Calvino, José J., Varela, Áurea, Sanchez, Clément, Parras, Marina, González-Calbet, José M., and Portehault, David

Abstract

Depto. de Química Inorgánica, Fac. de Ciencias Químicas, TRUE, pub

Published
2024

13. Composite MAX phase/MXene/Ni electrodes with a porous 3D structure for hydrogen evolution and energy storage application

Author

Sergiienko, Sergii A., primary, Lajaunie, Luc, additional, Rodríguez-Castellón, Enrique, additional, Constantinescu, Gabriel, additional, Lopes, Daniela V., additional, Shcherban, Nataliya D., additional, Calvino, José J., additional, Labrincha, João A., additional, Sofer, Zdenek, additional, and Kovalevsky, Andrei V., additional

Published
2024
Full Text
View/download PDF

16. Quantitative, Spectro-kinetic Analysis of Oxygen in Electron-Beam Sensitive, Multimetallic Oxide Nanostructures

Author

López-Haro, Miguel, primary, Gómez-Recio, Isabel, additional, Pan, Huiyan, additional, Delgado, Juan J, additional, Chen, Xiaowei, additional, Cauqui, Miguel A, additional, Pérez-Omil, José A, additional, Ruiz-González, María L, additional, Hernando, María, additional, Parras, Marina, additional, González-Calbet, José M, additional, and Calvino, José J, additional

Published
2023
Full Text
View/download PDF

17. Understanding the potential-induced activation of a cobalt MOF electrocatalyst for the oxygen evolution reaction

Author

Universidad de Sevilla. Departamento de Química Física, Ministerio de Ciencia e Innovación (MICIN). España, Unión Europea (EU), Junta de Andalucía, Gutiérrez Tarriño, Silvia, Portorreal Bottier, Arismendy Antonio, Trasobares, Susana, Calvente Pacheco, Juan José, Calvino, José J., Olloqui Sariego, José Luis, Oña Burgos, Pascual, Universidad de Sevilla. Departamento de Química Física, Ministerio de Ciencia e Innovación (MICIN). España, Unión Europea (EU), Junta de Andalucía, Gutiérrez Tarriño, Silvia, Portorreal Bottier, Arismendy Antonio, Trasobares, Susana, Calvente Pacheco, Juan José, Calvino, José J., Olloqui Sariego, José Luis, and Oña Burgos, Pascual

Abstract

Metal–organic frameworks (MOFs) are attractive porous materials for electrocatalytic applications associated with carbon-free energy storage and conversion. This type of material usually requires a post-treatment to be used as electrocatalyst. The present work comprehensively investigates the electrochemical activation of a cobalt-MOF@Nafion composite that produces outstanding electrocatalytic performance for the water oxidation reaction at neutral pH. A detailed electrochemical characterization reveals that the electroactivation of the composite requires the participation of the oxygen evolution reaction (OER) and leads to a significant increase in the electroactive population of cobalt centers. It is shown that an increase of the applied activation potential in the OER region results in a faster electroactivation of the Co-MOF without affecting the intrinsic electrocatalytic properties of the active cobalt centers, as evidenced by the unique linear correlation between the electrocatalytic OER current and the population of electroactive cobalt. In addition, at structural level, it is shown that the electrochemical activation causes the partial disruption of the Nafion adlayer, as well as morphological changes of the Co–MOF particles from a compact, rounded morphology, before electrochemical activation, to a more open and expanded structure, after electroactivation; with the concomitant increase of the number of surface–exposed cobalt centers. Interestingly, these cobalt centers retain their coordinative chemistry and their laminar distribution in the nanosheets at the nanoscale, which is consistent with the preservation of their intrinsic electrocatalytic activity after potential–induced activation. In this scenario, these results suggest that only the electroactivated cobalt centers with good accessibility to the electrolyte are electrochemically active. This work provides a better understanding of the processes and structural changes underlying the electrochemica

Published
2023

21. The impact of Mn nonstoichiometry on the oxygen mass transport properties of La0.8Sr0.2Mn y O3±δthin films

Author

Chiabrera, Francesco M, primary, Baiutti, Federico, additional, Börgers, Jacqueline M, additional, Harrington, George F, additional, Yedra, Lluís, additional, Liedke, Maciej O, additional, Kler, Joe, additional, Nandi, Pranjal, additional, Sirvent, Juan de Dios, additional, Santiso, Jose, additional, López-Haro, Miguel, additional, Calvino, José J, additional, Estradé, Sonia, additional, Butterling, Maik, additional, Wagner, Andreas, additional, Peiró, Francesca, additional, De Souza, Roger A, additional, and Tarancón, Albert, additional

Published
2022
Full Text
View/download PDF

22. High Angle Liquid Cell TEM Tomography for In Situ Observation and 3D Reconstruction in Liquid

Author

Das, Partha Pratim, primary, Cookman, Jennifer, additional, Pérez, Alejandro Gómez, additional, Plana-Ruiz, Sergi, additional, López-Haro, Miguel, additional, Calvino, José J, additional, Casablanca, Jesús Gonzalez, additional, Grivas, Evangelos, additional, Antipas, Georgios SE, additional, Ntallis, Nikolaos A, additional, and Nicolopoulos, Stavros, additional

Published
2022
Full Text
View/download PDF

23. Silver Clusters of Five Atoms as Highly Selective Antitumoral Agents Through Irreversible Oxidation of Thiols (Adv. Funct. Mater. 29/2022)

Author

Porto, Vanesa, primary, Buceta, David, additional, Domínguez, Blanca, additional, Carneiro, Carmen, additional, Borrajo, Erea, additional, Fraile, María, additional, Davila‐Ferreira, Nerea, additional, Arias, Iria R., additional, Blanco, José M., additional, Blanco, Maria C., additional, Devida, Juan M., additional, Giovanetti, Lisandro J., additional, Requejo, Félix G., additional, Hernández‐Garrido, Juan C., additional, Calvino, José J., additional, López‐Haro, Miguel, additional, Barone, Giampaolo, additional, James, Andrew M., additional, García‐Caballero, Tomás, additional, González‐Castaño, Diego M., additional, Treder, Martin, additional, Huber, Wolfgang, additional, Vidal, Anxo, additional, Murphy, Michael P., additional, López‐Quintela, M. Arturo, additional, and Domínguez, Fernando, additional

Published
2022
Full Text
View/download PDF

24. Segmentation of scanning-transmission electron microscopy images using the ordered median problem

Author

Universidad de Sevilla. Departamento de Estadística e Investigación Operativa, Universidad de Sevilla. FQM331: Metodos y Modelos de la Estadistica y la Investigacion Operativa, Calvino, José J., López Haro, Miguel, Muñoz Ocaña, Juan M., Puerto Albandoz, Justo, Rodríguez Chía, Antonio Manuel, Universidad de Sevilla. Departamento de Estadística e Investigación Operativa, Universidad de Sevilla. FQM331: Metodos y Modelos de la Estadistica y la Investigacion Operativa, Calvino, José J., López Haro, Miguel, Muñoz Ocaña, Juan M., Puerto Albandoz, Justo, and Rodríguez Chía, Antonio Manuel

Abstract

This paper presents new models for segmentation of 2D and 3D Scanning-Transmission Electron Micro- scope images based on the ordered median function. The main advantage of using this function is its good adaptability to the different types of images to be studied due to the wide range of weight vec- tors that can be cast. Classical segmentation models stand out for their ability to provide a segmentation of the original image very quickly and with low computational burden. However, they do not usually achieve high quality segmentations with a small number of clusters in order to classify the different ele- ments which compose the structure represented in the image. The quality of the segmentation provided by our approach is analysed using different choices of the weight vector in some real instances. More- over, improvements are proposed for the formulations to reduce the computational time needed to solve these problems by taking advantage of the weight vector structure.

Published
2022

26. The impact of Mn nonstoichiometry on the oxygen mass transport properties of La0.8Sr0.2MnyO3±δ thin films

Author

Chiabrera, Francesco M., Baiutti, Federico, Börgers, Jacqueline Marie, Harrington, George F., Yedra, Lluís, Liedke, Maciej O., Kler, Joe, Nandi, Pranjal, Sirvent, Juan de Dios, Santiso, Jose, López-Haro, Miguel, Calvino, José J., Estradé, Sonia, Butterling, Maik, Wagner, Andreas, Peiró, Francesca, De Souza, Roger, and Tarancón, Albert

Subjects
perovskite oxides, cation nonstoichiometry, antisite defects, LSM, ddc:530
Abstract

JPhys energy 4(4), 044011 (2022). doi:10.1088/2515-7655/ac98df, Published by IOP Publishing, Bristol

Published
2022

29. Photocatalytic removal of benzene over Ti3C2Tx MXene and TiO2–MXene composite materials under solar and NIR irradiation

Author

Sergiienko, Sergii A., primary, Tobaldi, David M., additional, Lajaunie, Luc, additional, Lopes, Daniela V., additional, Constantinescu, Gabriel, additional, Shaula, Aliaksandr L., additional, Shcherban, Nataliya D., additional, Shkepu, Viacheslav I., additional, Calvino, José J., additional, Frade, Jorge R., additional, Labrincha, João A., additional, and Kovalevsky, Andrei V., additional

Published
2022
Full Text
View/download PDF

31. Exceptional Low-Temperature CO Oxidation over Noble-Metal-Free Iron-Doped Hollandites: An In-Depth Analysis of the Influence of the Defect Structure on Catalytic Performance

Author

Gómez-Recio, Isabel, primary, Pan, Huiyan, additional, Azor-Lafarga, Alberto, additional, Ruiz-González, María Luisa, additional, Hernando, María, additional, Parras, Marina, additional, Fernández-Díaz, María Teresa, additional, Delgado, Juan J., additional, Chen, Xiaowei, additional, Jiménez, Daniel Goma, additional, Portehault, David, additional, Sanchez, Clément, additional, Cabero, Mariona, additional, Martínez-Arias, Arturo, additional, González-Calbet, José M., additional, and Calvino, José J., additional

Published
2021
Full Text
View/download PDF

32. Improving the reducibility of CeO2/TiO2 by high-temperature redox treatment: the key role of atomically thin CeO2 surface layers.

Author

Manzorro, Ramón, Montes-Monroy, José M., Goma-Jiménez, D., Calvino, José J., Pérez-Omil, José A., and Trasobares, S.

Abstract

CeO2/TiO2 catalysts treated in reaction environment at high temperatures evolve into complex and diverse systems, where several mixed oxides are formed. To analyze the redox behavior of this system, multiple oxidations and reducing thermal treatments have been applied. Results from the temperature-programmed reduction studies revealed a clear shift at lower temperatures on the reduction peak when the sample was previously reduced at high temperatures and oxidized under mild conditions. Meanwhile, the reduction peak was moved to high temperatures when the sample was previously reduced and oxidized at severe temperatures. The study, which was aimed at correlating this behavior with its chemical structure, was conducted using advanced electron microscopy, including high-resolution TEM and STEM imaging and spectroscopic techniques such as X-EDS and EELS. The data presented here comparing structures at the atomic level and chemical properties have uniquely unveiled that besides the cerium–titanium mixed oxides, a very thin layer up to a single monolayer was deposited along the TiO2 surface, which indeed was responsible for the improvement of the reducing temperature. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

33. Photocatalytic removal of benzene over Ti3C2Tx MXene and TiO2–MXene composite materials under solar and NIR irradiation.

Author

Sergiienko, Sergii A., Tobaldi, David M., Lajaunie, Luc, Lopes, Daniela V., Constantinescu, Gabriel, Shaula, Aliaksandr L., Shcherban, Nataliya D., Shkepu, Viacheslav I., Calvino, José J., Frade, Jorge R., Labrincha, João A., and Kovalevsky, Andrei V.

Abstract

MXenes, a family of two-dimensional (2D) transition metal carbides, nitrides and carbonitrides based on earth-abundant constituents, are prospective candidates for energy conversion applications, including photocatalysis. While the activity of individual MXenes towards various photocatalytic processes is still debatable, these materials were proved to be excellent co-catalysts, accelerating the charge separation and suppressing the exciton recombination. Titanium-containing MXenes are well compatible with the classical TiO2 photocatalyst. The TiO2 component can be directly grown on MXene sheets by in situ oxidation, representing a mainstream processing approach for such composites. In this study, an essentially different approach has been implemented: a series of TiO2–MXene composite materials with controlled composition and both reference end members were prepared, involving two different strategies for mixing sol–gel-derived TiO2 nanopowder with the Ti3C2Tx component, which was obtained by HF etching of self-propagating high-temperature synthesis products containing modified MAX phase Ti3C2Alz (z > 1) with nominal aluminium excess. The prospects of such composites for the degradation of organic pollutants under simulated solar light, using benzene as a model system, were demonstrated and analysed in combination with their structural, microstructural and optical properties. A notable photocatalytic activity of bare MXene under near infrared light was discovered, suggesting further prospects for light-to-energy harvesting spanning from UV-A to NIR and applications in biomedical imaging and sensors. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

34. A Novel Electron Microscopic Characterization of Core/Shell Nanobiostimulator Against Parasitic Plants

Author

Mejías, Francisco J. R., López-Haro, Miguel, Gontard, Lionel C., Cala, Antonio, Fernández-Aparicio, Mónica, Molinillo, José M. G., Calvino, José J., and Macías, Francisco A.

Abstract

Nanoencapsulation has proven to be an efficient route to increase significantly the solubility and bioavailability of organic compounds. This aspect of nanotechnology is illustrated for the case of phthalimide-lactone (PL), a recently synthesized strigolactone mimic whose very limited solubility in water, as a free chemical, precludes its practical use as an agrochemical in the fight against parasitic plants. Pluronic F-127 (P127) nanoparticles functionalized with PL have been synthesized and embedded in a polymeric matrix of poly(vinyl alcohol) (PVA). Low-voltage and medium voltage imaging and spectroscopic scanning electron microscopy (S(T)EM) techniques were combined to confirm the synthesis of multicore nanoparticles that were rich in nitrogen, a finding that is due to the successful encapsulation of PL. This PL@P127/PVA nanobiostimulator formulation has an impressive solubility in water, that is, 27 times higher than that of pure phthalimide-lactone. Also critical from the functional point of view, comparative bioassays clearly showed that the intrinsic stimulatory activity of this agrochemical is fully maintained in the nanoencapsulated formulation.

Published
2024
Full Text
View/download PDF

35. Correction: Photocatalytic removal of benzene over Ti3C2Tx MXene and TiO2–MXene composite materials under solar and NIR irradiation.

Author

Sergiienko, Sergii A., Tobaldi, David M., Lajaunie, Luc, Lopes, Daniela V., Constantinescu, Gabriel, Shaula, Aliaksandr L., Shcherban, Nataliya D., Shkepu, Viacheslav I., Calvino, José J., Frade, Jorge R., Labrincha, João A., and Kovalevsky, Andrei V.

Abstract

Correction for 'Photocatalytic removal of benzene over Ti3C2Tx MXene and TiO2–MXene composite materials under solar and NIR irradiation' by Sergii A. Sergiienko et al., J. Mater. Chem. C, 2022, 10, 626–639, https://doi.org/10.1039/D1TC03826E. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results