Publications 2018

Publications 20182020-05-07T10:59:25+02:00

Publications (2018)

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A new mechanistic model for an O-2-protected electron-bifurcating hydrogenase, Hnd from Desulfovibrio fructosovorans

Authors: Kpebe, A; Benvenuti, M; Guendon, C; Rebai, A; Fernandez, V; Le Laz, S; Etienne, E; Guigliarelli, B; Garcia-Molina, G; de Lacey, AL; Baffert, C; Brugna, M

Article.
Biochim. Biophys. Acta-Bioenerg.. vol: 1859. page: 0005-2728.
Date: DEC. 2018.
Doi: 10.1016/j.bbabio.2018.09.364.

Abstract:
The genome of the sulfate-reducing and anaerobic bacterium Desulfovibrio fructosovorans encodes different hydrogenases. Among them is Hnd, a tetrameric cytoplasmic [FeFe] hydrogenase that has previously been described as an NADP-specific enzyme (Malki et al., 1995). In this study, we purified and characterized a recombinant Strep-tagged form of Hnd and demonstrated that it is an electron-bifurcating enzyme. Flavin-based electron-bifurcation is a mechanism that couples an exergonic [read more]

Asymmetric and Selective Biocatalysis

Authors: Mateo, C; Palomo, JM

Editorial Material.
Catalysts. vol: 8. page: 2073-4344.
Date: DEC. 2018.
Doi: 10.3390/catal8120588.

Abstract:
The synthesis of compounds or chiral building-blocks with the desired configuration is one of the greatest challenges of chemistry and is of great interest in different fields such as analytical chemistry and especially in fine and pharmaceutical chemistry. […]

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Structural Insights into the Substrate Promiscuity of a Laboratory-Evolved Peroxygenase

Authors: Ramirez-Escudero, M; Molina-Espeja, P; de Santos, PG; Hofrichter, M; Sanz-Aparicio, J; Alcalde, M

Article.
ACS Chem. Biol.. vol: 13. page: 1554-8929.
Date: DEC. 2018.
Doi: 10.1021/acschembio.8b00500.

Abstract:
Because of their minimal requirements, substrate promiscuity and product selectivity, fungal peroxygenases are now considered to be the jewel in the crown of C-H oxyfunctionalization biocatalysts. In this work, the crystal structure of the first laboratory-evolved peroxygenase expressed by yeast was determined at a resolution of 1.5 A. Notable differences were detected between the evolved and native peroxygenase from Agrocybe aegerita, including the presence of a full N-terminus and a broader heme access channel due to the mutations [read more]

Further Stabilization of Alcalase Immobilized on Glyoxyl Supports: Amination Plus Modification with Glutaraldehyde

Authors: Hussain, F; Arana-Pena, S; Morellon-Sterling, R; Barbosa, O; Braham, SA; Kamal, S; Fernandez-Lafuente, R

Article.
Molecules. vol: 23. page: 1420-3049.
Date: DEC. 2018.
Doi: 10.3390/molecules23123188.

Abstract:
Alcalase was immobilized on glyoxyl 4% CL agarose beads. This permitted to have Alcalase preparations with 50% activity retention versus Boc-l-alanine 4-nitrophenyl ester. However, the recovered activity versus casein was under 20% at 50 degrees C, as it may be expected from the most likely area of the protein involved in the immobilization. The situation was different at 60 degrees C, where the activities of immobilized and free enzyme became similar. The chemical amination of the immobilized enzyme or [read more]

New insights about coke deposition in methanol-to-DME reaction over MOR-, MFI- and FER-type zeolites

Authors: Migliori, M; Catizzone, E; Aloise, A; Bonura, G; Gomez-Hortiguela, L; Frusteri, L; Cannilla, C; Frusteri, F; Giordano, G

Article.
J. Ind. Eng. Chem.. vol: 68. page: 1226-086X.
Date: DEC 25. 2018.
Doi: 10.1016/j.jiec.2018.07.046.

Abstract:
The effect of channel-system of zeolite on methanol-to-DME reaction was studied. Results revealed that channels size and topology affect catalyst lifetime, type and location of coke precursors. FER and MFI showed the best resistance towards coke deposition, whilst fast deactivation was observed on MOR. Although the higher concentration and strength of acid sites, FER structure formed a lower coke amount, preferably located within the pores, while coke cluster deposited on the [read more]

Hydrodeoxygenation of phenol on bifunctional Ni-based catalysts: Effects of Mo promotion and support

Authors: Kordouli, E; Pawelec, B; Kordulis, C; Lycourghiotis, A; Fierro, JLG

Article.
Appl. Catal. B-Environ.. vol: 238. page: 0926-3373.
Date: DEC 15. 2018.
Doi: 10.1016/j.apcatb.2018.07.012.

Abstract:
Hydrodeoxygenation (HDO) of phenol dissolved in decalin was studied over H-2-activated Ni and Mo-Ni catalysts supported on alumina and amorphous silica alumina (ASA) in the context of the O-removal from bio-liquids. The activity test was carried out in a flow reactor at 310 degrees C and total hydrogen pressure of 3 MPa. The catalyst samples were characterized by several physico-chemical techniques (S-BET, H-2-TPR, HRTEM, DRIFT spectroscopy of adsorbed CO and NH3, Raman spectroscopy, XPS, SEM-EDS and HRTEM) in order to [read more]

Novel (NH4)(4) [NiMo6O24H6]center dot 5H(2)O – TiO2 composite system: Photo oxidation of toluene under UV and sunlight-type illumination

Authors: Munoz-Batista, MJ; Bertolini, GR; Cabello, CI; Luque, R; Rodriguez-Castellon, E; Kubacka, A; Fernandez-Garcia, M

Article.
Appl. Catal. B-Environ.. vol: 238. page: 0926-3373.
Date: DEC 15. 2018.
Doi: 10.1016/j.apcatb.2018.07.041.

Abstract:
A series of composite materials based on titania and growing quantities of the (NH4)(4)[NiMo6O24H6]center dot 5H(2)O heteropolyacid (NiMo6 HPA) was tested in the gas-phase toluene photo-oxidation reaction. Materials were characterized with the help of chemical analysis, X-ray diffraction, porosimetry, electron transmission and scanning microscopies, as well as X-ray photoelectron and UV visible diffuse-reflectance spectroscopies. Photo activity performance was assessed under UV and sunlight-type illumination conditions through the calculation of the true quantum efficiency to measure activity [read more]

Enhancing photocatalytic performance of TiO2 in H-2 evolution via Ru co-catalyst deposition

Authors: Ouyang, WY; Munoz-Batista, MJ; Kubacka, A; Luque, R; Fernandez-Garcia, M

Article.
Appl. Catal. B-Environ.. vol: 238. page: 0926-3373.
Date: DEC 15. 2018.
Doi: 10.1016/j.apcatb.2018.07.046.

Abstract:
A series of ruthenium catalysts supported into pure anatase titania were tested in the photo-production of hydrogen from methanol:water mixtures under UV and visible illumination conditions. Catalysts containing 1, 2, 3 and 5 wt% of ruthenium were subjected to a characterization study with the help of X-ray diffraction, Raman, X-ray photoelectron spectroscopy, photoluminescence, morphology as well as scanning and transmission electron microscopy. Through the measurement of the optical properties of the suspension of the catalysts and the hydrogen photo-production reaction [read more]

Bimetallic Pt-Pd co-catalyst Nb-doped TiO2 materials for H-2 photo-production under UV and Visible light illumination

Authors: Caudillo-Flores, U; Munoz-Batista, MJ; Fernandez-Garcia, M; Kubacka, A

Article.
Appl. Catal. B-Environ.. vol: 238. page: 0926-3373.
Date: DEC 15. 2018.
Doi: 10.1016/j.apcatb.2018.07.047.

Abstract:
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, Xray 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 [read more]

PtSn nanoparticles supported on titanium carbonitride for the ethanol oxidation reaction

Authors: Roca-Ayats, M; Guillen-Villafuerte, O; Garcia, G; Soler-Vicedo, M; Pastor, E; Martinez-Huerta, MV

Article.
Appl. Catal. B-Environ.. vol: 237. page: 0926-3373.
Date: DEC 5. 2018.
Doi: 10.1016/j.apcatb.2018.05.078.

Abstract:
The effect of titanium carbonitride (TiCN) as a new support for platinum-tin nanoparticulated catalysts for the ethanol oxidation reaction (EOR) in acid medium was evaluated. For that purpose, two platinum-tin catalysts supported on TiCN and carbon black (Vulcan XC-72R) were synthesized following the ethylene glycol method. XRD, TEM, ICP-OES and XPS techniques revealed that both catalysts exhibit similar physicochemical properties. However, the EOR and the CO tolerance were enhanced at the catalyst supported on TiCN. In situ Fourier [read more]

Two-dimensional Pd-nanosheets as efficient electrocatalysts for ethanol electrooxidation. Evidences of the C-C scission at low potentials

Authors: Farsadrooh, M; Torrero, J; Pascual, L; Pena, MA; Retuerto, M; Rojas, S

Article.
Appl. Catal. B-Environ.. vol: 237. page: 0926-3373.
Date: DEC 5. 2018.
Doi: 10.1016/j.apcatb.2018.06.051.

Abstract:
Pd-nanosheets with a lateral size of ca. 5 nm have been prepared by a simple chemical method. The Pd-nanosheets obtained exhibited a 2D morphology in which Pd atoms are preferentially exposed at the surface of the particles. In addition, a preferential exposure of Pd atoms in 111 planes is observed. As a result, the Pd-nanosheets exhibit a very high catalytic activity for the electrooxidation of ethanol in alkaline electrolyte, superior to that of commercial nanosized Pd particles. In [read more]

Effect of partial Mo substitution by W on HDS activity using sulfide CoMoW/Al2O3-TiO2 catalysts

Authors: Obeso-Estrella, R; Fierro, JLG; de Leon, JND; Fuentes, S; Alonso-Nunez, G; Lugo-Medina, E; Pawelec, B; Zepeda, TA

Article.
Fuel. vol: 233. page: 0016-2361.
Date: DEC 1. 2018.
Doi: 10.1016/j.fuel.2018.06.078.

Abstract:
A series of Al2O3-TiO2-supported trimetallic CoMoW catalysts were prepared with the aim to study the effect of Mo substitution by W on the catalyst performance in deep hydrodesulfurization (HDS) reaction. The oxide catalyst precursors were characterized by N-2 physisorption, temperature-programmed desorption of NH3 (TPD-NH3), temperature-programmed reduction (TPR), diffuse reflectance spectroscopy (DRS UV-vis) and Raman spectroscopy. Sulfided catalysts were characterized by X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM), and tested in the [read more]

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 [read more]

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 [read more]

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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 [read more]

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