Publicaciones 2018

Publicaciones 20182020-05-07T11:00:06+02:00

Publicaciones (2018)

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Publicaciones 2020
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XAS/DRIFTS/MS spectroscopy for time-resolved operando investigations at high temperature

Authors: Agostini, G; Meira, D; Monte, M; Vitoux, H; Iglesias-Juez, A; Fernandez-Garcia, M; Mathon, O; Meunier, F; Berruyer, G; Perrin, F; Pasternak, S; Mairs, T; Pascarelli, S; Gorges, B

Article.
J. Synchrot. Radiat.. vol: 25. page: 1600-5775.
Date: NOV. 2018.
Doi: 10.1107/S160057751801305X.

Abstract:
The combination of complementary techniques in the characterization of catalysts under working conditions is a very powerful tool for an accurate and in-depth comprehension of the system investigated. In particular, X-ray absorption spectroscopy (XAS) coupled with diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and mass spectroscopy (MS) is a powerful combination since XAS characterizes the main elements of the catalytic system (selecting the [leer más]

Preparation of Magnetic Cross-Linked Amyloglucosidase Aggregates: Solving Some Activity Problems

Authors: Amaral-Fonseca, M; Kopp, W; Giordano, RDC; Fernandez-Lafuente, R; Tardioli, PW

Article.
Catalysts. vol: 8. page: 2073-4344.
Date: NOV. 2018.
Doi: 10.3390/catal8110496.

Abstract:
The preparation of Cross-Linked Enzyme Aggregates (CLEAs) is a simple and cost-effective technique capable of generating insoluble biocatalysts with high volumetric activity and improved stability. The standard CLEA preparation consists of the aggregation of the enzyme and its further crosslinking, usually with glutaraldehyde. However, some enzymes have too low a content of surface lysine groups to permit effective crosslinking with glutaraldehyde, requiring co-aggregation with feeders rich in amino groups to aid the formation of CLEAs. The co-aggregation with magnetic particles makes their handling [leer más]

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Porosity Reduction in New Thin Films of Ceramic Coatings on Stainless Steel by Annealing at Reduced Pressure

Authors: Cubillos, GI; Bethencourt, M; Alfonso, JE; Rodriguez-Castellon, E; Romero, E

Article.
Metall. Mater. Trans. A-Phys. Metall. Mater. Sci.. vol: 49A. page: 1073-5623.
Date: NOV. 2018.
Doi: 10.1007/s11661-018-4888-5.

Abstract:
New ZrOxNy thin films were deposited via reactive RF magnetron sputtering on stainless steel substrate from a Y2O3-doped ZrO2 (3YSZ) target. In order to reduce their porosity and increase corrosion resistance, the films were annealed at 265 degrees C in an inert atmosphere at reduced pressure, increasing their density and corrosion resistance in saline solution. The crystal structure of the films was characterized by means of X-ray diffraction, the morphology via scanning electron microscopy and atomic force [leer más]

High-Performance Photocatalytic Hydrogen Production and Degradation of Levofloxacin by Wide Spectrum-Responsive Ag/Fe3O4 Bridged SrTiO3/g-C3N4 Plasmonic Nanojunctions: Joint Effect of Ag and Fe3O4

Authors: Kumar, A; Rana, A; Sharma, G; Naushad, M; Al-Muhtaseb, AH; Guo, CS; Iglesias-Juez, A; Stadler, FJ

Article.
ACS Appl. Mater. Interfaces. vol: 10. page: 1944-8244.
Date: nov-28. 2018.
Doi: 10.1021/acsami.8b12753.

Abstract:
Highly photoresponsive semiconductor photocatalysis for energy and environmental applications require judicious choice and optimization of semiconductor interfaces for wide spectral capabilities. This work aims at rational designing of highly active SrTiO3/g-C3N4 junctions bridged with Ag/Fe3O4 nanoparticles for utilizing Z-scheme transfer and surface plasmon resonance effect of Ag augmented by iron oxide. The SrTiO3/(Ag/Fe3O4)/g-C3N4 (SFC) catalyst was employed for photocatalytic hydrogen production and photodegradation of levofloxacin (LFC; 20 mg/L) under UV, visible, near infra-red, and [leer más]

Synthesis of mesoporous-zeolite materials using Beta zeolite nanoparticles as precursors and their catalytic performance in m-xylene isomerization and disproportionation

Authors: Chaida-Chenni, FZ; Belhadj, F; Casas, MSG; Marquez-Alvarez, C; Hamacha, R; Bengueddach, A; Perez-Pariente, J

Article.
Appl. Catal. A-Gen.. vol: 568. page: 0926-860X.
Date: nov-25. 2018.
Doi: 10.1016/j.apcata.2018.10.005.

Abstract:
Hierarchical Beta nanozeolites with the properties of both Beta nanozeolite and mesoporous material were prepared by two different methods: (1) Direct Hydrothermal Method (DHM) by the assembly of nanocrystals of preformed Beta seeds in the presence of the surfactant P123 under hydrothermal conditions, (2) Acidification of Beta seeds suspension (without the use of the mesopore directing agent). For the two methods, the effect of crystallization time of Beta nanozeolite precursor (seeds) was studied: 6, 12 and 24 [leer más]

Experimental and Theoretical Study on the Nature of Adsorbed Oxygen Species on Shaped Ceria Nanoparticles

Authors: Schilling, C; Ganduglia-Pirovano, MV; Hess, C

Article.
J. Phys. Chem. Lett.. vol: 9. page: 1948-7185.
Date: nov-15. 2018.
Doi: 10.1021/acs.jpclett.8b02728.

Abstract:
Ceria is widely used in heterogeneous catalysis owing to its redox properties. Engineering the shape of ceria particles offers a powerful tool to develop materials with enhanced catalytic properties. In this study, we provide evidence for the shape dependent dioxygen adsorption and activation of ceria nanoparticles with (111) and (100) facets by in situ Raman spectroscopy and relate these properties to unique adsorption sites employing density functional theory. Temperature- and gas-phase-dependent experiments demonstrate facilitated formation of peroxide, superoxide, and weakly bound dioxygen species on [leer más]

RETRACTION: Microwave-activated direct synthesis of acrylonitrile from glycerol under mild conditions: effect of niobium as dopant of the V-Sb oxide catalytic system (Retraction Article, vol 95, pg 192, 2010)

Authors: Calvin-Casilda, V; Guerrero-Perez, MO; Banares, MA

Retraction.
Appl. Catal. B-Environ.. vol: 236. page: 0926-3373.
Date: nov-15. 2018.
Doi: 10.1016/j.apcatb.2018.05.088.

Abstract:
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Role of lattice oxygen content and Ni geometry in the oxygen evolution activity of the Ba-Ni-O system

Authors: Retuerto, M; Calle-Vallejo, F; Pascual, L; Ferrer, P; Garcia, A; Torrero, J; Gianolio, D; Fierro, JLG; Pena, MA; Alonso, JA; Rojas, S

Article.
J. Power Sources. vol: 404. page: 0378-7753.
Date: nov-15. 2018.
Doi: 10.1016/j.jpowsour.2018.09.098.

Abstract:
The activity of oxides towards the oxygen evolution reaction (OER) is usually tuned by changing the transition metal components and/or the surface facets. An important yet less studied feature is the repercussion of the lattice oxygen content of the oxide in the active site’s coordination and catalytic performance. This is illustrated here for the Ba-Ni-O system. We synthesized two oxides with Ni in different coordination and oxidation states, namely [leer más]

Y zeolite-supported niobium pentoxide catalysts for the glycerol acetalization reaction

Authors: Ferreira, C; Araujo, A; Calvino-Casilda, V; Cutrufello, MG; Rombi, E; Fonseca, AM; Banares, MA; Neves, IC

Article.
Microporous Mesoporous Mat.. vol: 271. page: 1387-1811.
Date: nov-15. 2018.
Doi: 10.1016/j.micromeso.2018.06.010.

Abstract:
Faujasite zeolite-supported niobium-based catalysts (with Nb2O5 amounts of 5 and 15 wt%) were prepared by impregnation of NaY, HY, and HUSY zeolites using a niobum(V) ammonium oxalate complex. These obtained Nb-containing catalysts were calcined and thoroughly characterized by different physico-chemical techniques. The characterization results revealed that niobium oxide was successfully loaded on the surface of the zeolite supports without any significant modification of the faujasite structure. Surface area and pore volume were found to decrease [leer más]

Sunlight-Driven Hydrogen Production Using an Annular Flow Photoreactor and g-C3N4-Based Catalysts

Authors: Munoz-Batista, MJ; Rodriguez-Padron, D; Puente-Santiago, AR; Kubacka, A; Luque, R; Fernandez-Garcia, M

Article.
ChemPhotoChem. vol: 2. page: 2367-0932.
Date: OCT. 2018.
Doi: 10.1002/cptc.201800064.

Abstract:
Simple modifications of g-C3N4 (CN) have been studied to maximize hydrogen production under sunlight irradiation conditions. The relatively low surface area CN obtained was subjected to an exfoliation process which 1) increases available catalytic area and 2) modulates the semiconductor charge photohandling. MnOx and metallic Pt, which can act as co-catalysts, were subsequently added on the surface of exfoliated or bulk counterparts, producing an active material suitable for sunlight applications. The resulting catalysts were fully characterized using a multi-technique approach. The [leer más]

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Influence of different immobilization techniques to improve the enantioselectivity of lipase from Geotrichum candidum applied on the resolution of mandelic acid

Authors: de Morais, WG; Maia, AM; Martins, PA; Fernandez-Lorente, G; Guisan, JM; Pessela, BC

Article.
Mol. Catal.. vol: 458. page: 2468-8231.
Date: OCT. 2018.
Doi: 10.1016/j.mcat.2018.07.024.

Abstract:
Enzymes’ stabilization degree and protein structure modification have been associated with different immobilization techniques. Geotrichum candidum lipase (GCL) was immobilized using different supports and immobilization protocols: covalent bonding on Cyanogen bromide activated sepharose (CNBr) and amino-glyoxyl (AMG), and ionic bonding on anionic support diethylaminoethyl (DEAE) and cationic support carboxymethyl agarose. The lipase stability in medium with different pH values and thermal stability of different derivatives of GCL were evaluated for enantioselective hydrolysis of (R,S)-mandelic acid ethyl ester under different [leer más]

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Immobilization of beta-galactosidase in glutaraldehyde-chitosan and its application to the synthesis of lactulose using cheese whey as feedstock

Authors: de Albuquerque, TL; Gomes, SDL; D’Almeida, AP; Fernandez-Lafuente, R; Goncalves, LRB; Rocha, MVP

Article.
Process Biochem.. vol: 73. page: 1359-5113.
Date: OCT. 2018.
Doi: 10.1016/j.procbio.2018.08.010.

Abstract:
The aim of this work was to establish optimal conditions for the enzymatic production of lactulose by beta-galactosidase from Kluyveromyces lactis using cheese whey as feedstock. Initially, the production of this disaccharide was evaluated using free beta-galactosidase and synthetic medium (containing lactose and fructose), and the optimal conditions for the production of lactulose were as follows: lactose/fructose ratio of 15/30% (w/v); total initial concentration of lactose and fructose of 200 g/L; and operational conditions at 50 degrees C, pH [leer más]

Solid phase chemical modification of agarose glyoxyl-ficin: Improving activity and stability properties by amination and modification with glutaraldehyde

Authors: Siar, E; Arana-Pena, S; Barbosa, O; Zidoune, MN; Fernandez-Lafuente, R

Article.
Process Biochem.. vol: 73. page: 1359-5113.
Date: OCT. 2018.
Doi: 10.1016/j.procbio.2018.07.013.

Abstract:
Ficin extract immobilized on glyoxyl-agarose was chemically modified using carbodiimide and ethylenediamine (full or partial amination of the carboxylic groups of the enzyme) or glutaraldehyde (modifying primary amino groups) under different conditions. Aminated enzyme altered its activity versus casein and benzoyl-arginine-p-nitroanilide (BANA), e.g., the activity versus casein even slightly increased while versus BANA it decreased, being this more significant at pH 9 (the fully aminated biocatalyst increased the activity versus casein by 10% but it decreased more than 5 folds versus BANA), [leer más]

Elucidation of the photocatalytic-mechanism of phenolic compounds

Authors: Tolosana-Moranchel, A; Montejano, A; Casas, JA; Bahamonde, A

Article.
J. Environ. Chem. Eng.. vol: 6. page: 2213-2929.
Date: OCT. 2018.
Doi: 10.1016/j.jece.2018.08.068.

Abstract:
In the present work, phenol and other phenolic compounds (4-chlorophenol, 4-nitrophenol and methyl p-hydroxybenzoate) as typical aromatic pollutants were selected to investigate and elucidate their photocatalytic-mechanism over two commercial TiO2 catalysts: Hombikat UV-100 and Aeroxide (R) P25, with different physico-chemical properties. To try to clarify which pathway is more relevant in the corresponding photodegradation mechanism, the following scavengers were employed: formic acid (scavenger of photogenerated holes), methanol (strong hydroxyl radical scavenger) and cupper (II) nitrate (scavenger of electrons from conduction band). Higher [leer más]

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Efficient conversion of chitosan into chitooligosaccharides by a chitosanolytic activity from Bacillus thuringiensis

Authors: Santos-Moriano, P; Kidibule, PE; Alleyne, E; Ballesteros, AO; Heras, A; Fernandez-Lobato, M; Plou, FJ

Article.
Process Biochem.. vol: 73. page: 1359-5113.
Date: OCT. 2018.
Doi: 10.1016/j.procbio.2018.07.017.

Abstract:
Starting from a commercial preparation of Bacillus thuringiensis var. aizawai, widely employed as biopesticide in agriculture, we obtained a chitosanolytic activity by washing the cells with concentrated sodium acetate. The optimum pH and temperature values for this enzyme were 6.0 and 60 degrees C, respectively. The enzymatic extract efficiently hydrolyzed various chitosans with different deacetylation degrees (DD) into small oligosaccharides. Combining mass spectrometry (ESI-Q-TOF) and high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD), we observed the formation of [leer más]

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