Catalizadores metálicos subnanométricos altamente eficientes en reacciones de formación de enlaces C-C

[ES] De forma general, el trabajo realizado durante la presente tesis doctoral se ha enfocado al diseño y optimización de catalizadores heterogéneos basados en Pd y Ru soportado sobre óxidos metálicos y materiales carbonosos. A fin de optimizar los catalizadores se han relacionado los ensayos catalíticos con las propiedades físico-químicas de los materiales mediante diferentes técnicas (XPS, HAADF-STEM, Fotoluminiscencia, IR, ¿) siguiendo un proceso iterativo de ensayo-caracterización-optimización. En concreto, la presente tesis doctoral se puede dividir en dos partes en función de las reacciones estudiadas: 1. Durante la primera parte, capítulo 3, se han preparado catalizadores basados en Au, Pd y Pd(OH)2 soportado sobre diferentes óxidos metálicos con objeto de realizar el homoacoplamiento oxidativo de benzoato de metilo en ausencia de disolvente y empleando oxígeno como único agente oxidante. Se ha conseguido identificar la especie activa como clústeres de Pd mediante el empleo de espectroscopia de infrarrojo de adsorción de CO y fotoluminiscencia. Con este conocimiento se ha podido diseñar un pre-tratamiento de activación específico para maximizar la actividad catalítica con el cual se ha logrado obtener un rendimiento catalítico similar al del catalizador homogéneo de Pd(OAc)2. 2. En la segunda parte de la tesis, se ha estudiado la hidroformilación de 1-hexeno empleando catalizadores alternativos basados en Ru. En particular, durante el capítulo 4 se han desarrollado catalizadores de Ru soportados sobre una matriz orgánica-inorgánica compuesta por un biopolímero natural, quitosán, y SiO2 detectándose un efecto sinérgico entre las especies lixiviadas de Ru (TON > 3000, TOF > 550 h-1) y los grupos funcionales del quitosán que ha sido estudiado mediante espectroscopia de absorción de rayos-X. Finalmente, el objetivo del capítulo 5 ha sido estabilizar las especies de Ru mediante un tratamiento térmico de pirólisis. Empleando un biopolímero natural se ha conseguido diseñar un catalizador estable, capaz de hidroformilar selectivamente el enlace terminal de olefinas de diferente tamaño de cadena con alta regioselectividad (S > 90%) que puede ser re-usado. Gracias al uso de técnicas espectroscópicas avanzadas se ha podido relacionar la actividad intrínseca de las especies de Ru soportadas identificándose a los átomos aislados de Ru como los más activos (TOF > 12.000 h-1).[CA] This doctoral thesis has focused on the design and optimization of heterogeneous Pd and Ru catalysts supported on metallic oxides and carbon materials. In order to optimize the catalysts a relationship has been stablished between the observed reaction kinetics and the physico-chemical properties of the materials by means of different characterization techniques (XPS, HAADF-STEM, photoluminescence, IR ¿) following an iterative kinetic test-characterization-optimization process. In particular, this thesis can be divided in two different parts depending on the reaction studied: 1. In chapter 3, different catalysts based on Au, Pd and Pd(OH)2 supported on a variety of mixed oxides have been prepared with the aim of performing the oxidative homocoupling of methyl benzoate in absence of solvent with molecular oxygen as the only oxidising agent. In this case, Pd clusters have been identified as the active species by means of photoluminescence and infrared spectroscopy using CO as probe molecule. After identifying the active species, a specific activation pre-treatment could be designed in order to maximize the catalytic activity which is on par with the homogeneous Pd(OAc)2 counterpart. 2. In the next chapter (Chapter 4), the hydroformylation of 1-hexene using alternative Ru based catalysts was studied. In particular, a series of hybrid organic-inorganic Ru catalysts composed of a natural biopolymer, chitosan, and SiO2 were developed which showed and interesting synergistic effect between the lixiviated species of Ru and the functional groups of chitosan. This effect was studied by X-ray absorption spectroscopy. The catalyst showed a high activity (TON > 3000 and TOF > 550 h-1) as well as a high regioselectivity towards formation of lineal aldehyde (S > 95%). 3. Finally, the objective of chapter 5 was to go one step further trying to stabilize the Ru species observed in previous chapter by means of a pyrolytic thermal treatment. Thus, with the aid of a natural biopolymer and a carbonaceous support the goal of designing a reusable and stable catalyst, able to selectively catalyse the hydroformylation of terminal olefins with variable chain length and high regioselectivity (S > 90%) towards the lineal aldehyde was successfully achieved. In this case, the intrinsic activity of the different Ru supported entities was studied by advanced spectroscopy techniques allowing the identification of isolated single Ru atoms as the most active catalytic centers (TOF > 12000 h-1)[EN] En general, el treball realitzat durant la present tesi doctoral s'ha centrat en l'optimització de catalitzadors heterogenis basats en Pd i Ru suportat sobre òxids metàl·lics i materials carbonacis. Amb l'objectiu d'optimitzar els catalitzadors, s'ha establert una relació entre els resultats dels experiments catalítics i les propietats fisicoquímiques dels materials mitjançant la utilització de diferents tècniques (XPS, HAADF - STEM, fotoluminescència, IR,...) seguint un esquema iteratiu d'assaig - caracterització - optimització. En concret, la present tesi doctoral es pot dividir en dos parts, en funció de les reaccions estudiades: 1. En la primera part, capítol 3, s'han preparat catalitzadors basats en Au, Pd i Pd(OH)2 suportat sobre diferents òxids metàl·lics amb l'objectiu de realitzar la reacció d'homoacoblament oxidatiu del benzoat de metil en absència de dissolvent i utilitzant oxigen com a únic agent oxidant. S'ha aconseguit identificar els clústers de Pd com a espècies actives de la reacció gràcies a l'espectroscòpia d'infraroig d'adsorció de CO i a la fotoluminescència. D'aquesta forma, s'ha pogut dissenyar un pretractament d'activació específic per aconseguir maximitzar l'activitat catalítica. S'han aconseguit obtenir uns valors de rendiment catalític similars al presentats pel catalitzador homogeni Pd(OAc)2. 2. En la segona part de la tesi, s'ha estudiat la hidroformilació de l'1-hexè utilitzant catalitzadors alternatius basats en Ru. En concret, en el capítol 4, s'han desenvolupat catalitzadors de Ru suportats sobre una matriu orgànica - inorgànica constituïda per un biopolímer natural, quitosan, i SiO2. Així doncs, s'ha pogut detectar un efecte sinèrgic entre les espècies lixiviades de Ru (TON > 3000 and TOF > 550 h-1) i els grups funcionals del quitosan. Dit efecte s'ha estudiat per mitjà de l'espectroscòpia d'absorció de rajos X. Finalment, l'objectiu del capítol 5 ha consistit en estabilitzar les espècies de Ru per mitjà d'un tractament tèrmic de piròlisis. Utilitzant un biopolímer natural, s'ha aconseguit dissenyar un catalitzador estable, capaç d'hidroformilar selectivament i amb una elevada regioselectivitat (S> 90%) l'enllaç terminal d'olefines de diferent longitud; i poder ésser posteriorment reutilitzat. A partir de tècniques d'espectroscòpia avançades, s'ha pogut relacionar l'activitat intrínseca de les espècies de Ru suportades, i s'han identificat els àtoms aïllats de Ru com aquelles espècies més actives (TOF > 12.000 h-1).Escobar Bedia, FJ. (2021). Catalizadores metálicos subnanométricos altamente eficientes en reacciones de formación de enlaces C-C [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172628TESI

Active and Regioselective Ru Single-Site Heterogeneous Catalystsfor Alpha-Olefin Hydroformylation

[EN] A heterogeneous ruthenium catalyst consisting ofisolated single atoms and disordered clusters stabilized in a N-doped carbon matrix has been synthesized with very good activityand remarkable regioselectivity in the hydroformylation of 1-hexene. The role of the nitrogen heteroatoms has been probedessential to increase the catalyst stability and activity, enabling thestabilization of Ru(II)-N sites according to X-ray photoelectronspectroscopy (XPS) and XANES. Intrinsic size-dependent activityof Ru species of different atomicity has been extracted, correlatingthe observed reaction rate and the particle size distributiondetermined by means of aberration-corrected high-angle annulardark-field scanning transmission electron microscopy, permittingthe identification of single-atom sites as the most active ones. This catalyst appears as a promising alternative with respect to itsheterogeneous counterparts, paving the way for designing improved Ru heterogeneous catalysts.The research leading to these results has received funding from the Spanish Ministry of Science, Innovation and Universities, through the "Severo Ochoa" Excellence Programme (SEV2016-0683) and RTI2018-099668-B-C21 and PGC2018101247-B-100 "Programa Estatal de Generacion de Conocimiento". P.C acknowledges the financial support from the "Generalitat Valenciana" through the project AICO/2020/205. HR-HAADF-STEM measurements were performed at the DME-UCA node of ELECMI ICTS with financial support from FEDER/MINECO (MAT2017-87579-R and PID2019110018GA-I00); XAS experiments were performed at the BL22-CLAESS beamline at the ALBA Synchrotron with the collaboration of ALBA staff as part of projects 2019093692 and 2020024106. XPS experiments were performed at the BL24CIRCE beamline at the ALBA Synchrotron with the collaboration of ALBA staff. J.E.B acknowledges the Polytechnical University of Valencia for the economic support through the grant of an FPI scholarship associated with the PAID programme "Programa de Ayudas de Investigacion y Desarrollo".Escobar-Bedia, FJ.; Lopez-Haro, M.; Calvino, JJ.; Martin-Diaconescu, V.; Simonelli, L.; Pérez-Dieste, V.; Sabater Picot, MJ.... (2022). Active and Regioselective Ru Single-Site Heterogeneous Catalystsfor Alpha-Olefin Hydroformylation. ACS Catalysis. 12(7):4182-4193. https://doi.org/10.1021/acscatal.1c057374182419312

Bifunctional atomically dispersed ruthenium electrocatalysts for efficient bipolar membrane water electrolysis

Atomically dispersed catalysts (ADCs) have recently drawn considerable interest for use in water electrolysis to produce hydrogen, because they allow for maximal utilization of metal species, particularly the expensive and scarce platinum group metals. Herein, we report the electrocatalytic performance of atomically dispersed ruthenium catalysts (Ru ADCs) with ultralow Ru loading (0.2 wt%). The as-obtained Ru ADCs (Ru (0.2)-NC) are active for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), which only require a low overpotential (η) of 47.1 and 72.8 mV to deliver 10 mA cm for HER in 0.5 M HSO and 1.0 M KOH, respectively, and of 300 mV for OER in 1.0 M KOH, showing favorable bifunctionality. Density functional theory (DFT) calculations reveal that the Ru-N bonding plays an important role in lowering the energy barrier of the reactions, boosting the HER and OER activities. Furthermore, the bipolar membrane (BPM) water electrolysis using the bifunctional Ru (0.2)-NC as both HER and OER catalysts can afford 10 mA cm under a low cell voltage of only 0.89 V, and does not show any performance decay upon 100 h continuous operation, showing great potential for energy-saving hydrogen production.L. L. acknowledges the financial support from the National Innovation Agency of Portugal through the Mobilizador Programme (Baterias 2030, Grant No. POCI-01-0247-FEDER-046109). B. L. acknowledges the Natural Science Foundation of LiaoNing Province, China (Grant No. 20180510014) for funding. Z. P. Y. is grateful for the scholarship offered by the China Scholarship Council (Grant No. 201806150015). This work was also in part financially supported by: LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and UIDP/50020/2020 (LSRE-LCM) funded by national funds through FCT/MCTES (PIDDAC); project 2DMAT4FUEL (POCI-01-0145-FEDER-029600 - COMPETE2020 – FCT/MCTES - PIDDAC, Portugal). In addition, this work was carried out in part through the use of the INL Advanced Electron Microscopy, Imaging and Spectroscopy (AEMIS) Facility

Chitosan-Silica as a Cheap Carrier and Green Soft Ligand for Improved Ru-catalyzed Hydroformylation

Dodecacarbonyltriruthenium Ru(CO) has been immobilized onto a biopolymer (chitosan) supported on SiO (Ch@SiO) to give Ru−Ch@SiO. Ch@SiO behaves as a soft, recoverable and bulky ligand allowing the stabilization of released Ru active species and preventing its irreversible reduction to Ru. Under these conditions very high activity (TOF= 1086 h; TON=2749) and regioselectivity (n:iso=92 : 8) are obtained, surpassing that of the homogeneous Ru(CO) counterpart. Spectroscopic studies have shown that Ru(CO) transforms into a mononuclear Ru (n=2,3) di o try carbonyl species by interacting with the amido/amino groups of the biopolymer, being released into the reaction media whilst stabilized by the chitosan functional groups. The herein 0.5 Ru-Ch@SiO catalyst can operate be operated under a semi-continuous mode for at least 14 h without deactivation, representing providing a starting point in the search for a green catalyst with definitive industrial application in hydroformylations. In particular in the search for a heterogeneous catalyst away from the use of phosphines and their known drawbacks (i. e. tedious synthesis, facile oxidation of phosphor center,.) as well as expensive Rh as active site.This research was funded by Ministerio de Ciencia, Innovación y Universidades, Grants number RTI2018-099668-B-C21 and PGC2018-101247-B-100, and Generalitat Valenciana (GVA), AICO/2020/205. F.J.E.B acknowledges the Polytechnical University of Valencia for the economic support through the grant of an FPI scholarship associated with the PAID programme “Programa de Ayudas de Investigación y Desarrollo”. XAS experiments were performed at the BL22-CLÆSS beamline at the ALBA Synchrotron with the collaboration of ALBA staff as part of projects 2019093692 and 2020024106

Composición basada en la actividad antioxidante de la enzima superóxido dismutasa y su aplicación en enfermedades oculares

La presente invención se refiere a la composición que contiene una enzima perteneciente al grupo de las superóxido dismutasas (SOD), o bien cualquier mímico de la SOD y similares junto con ácido hialurónico y EDTA. Dicha composición forma parte de una formulación farmacéutica la cual promueve o mantiene la salud ocular a través de la inhibición del daño celular y tisular producido por radicales libres, por lo que es útil en el tratamiento y/o prevención de enfermedades oculares que cursan con estrés oxidativo, o como coadyuvante de otros tratamientos existentes, así como posoperatorios para tratar y/o prevenir reacciones adversas inflamatorias o estrés oxidativoPeer reviewedFundación para el fomento de la investigación sanitaria y biomédica de la Comunidad Valenciana (FISABIO), Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Cardenal Herrera CEU San Pablo, Universitat de ValènciaA1 Solicitud de patente con informe sobre el estado de la técnic

Composition basée sur l'activité antioxydante de l'enzyme superoxyde dismutase et son application dans des maladies oculaires

[EN] The present invention relates to a composition containing an enzyme belonging to the group of superoxide dismutases (SOD), or any SOD mimic and similar, together with hyaluronic acid and EDTA. Said composition forms part of a pharmaceutical formulation which promotes or maintains eye health by inhibiting cellular and tissue damage caused by free radicals, making it useful in the treatment and/or prevention of eye diseases involving oxidative stress, or as an adjuvant to other existing treatments, as well as in post-operative treatments to treat and/or prevent oxidative stress or inflammatory adverse reactions.[ES] La presente invención se refiere a la composición que contiene una enzima perteneciente al grupo de las superóxido dismutasas (SOD), o bien cualquier mímico de la SOD y similares junto con ácido hialurónico y EDTA. Dicha composición forma parte de una formulación farmacéutica la cual promueve o mantiene la salud ocular a través de la inhibición del daño celular y tisular producido por radicales libres, por lo que es útil en el tratamiento y/o prevención de enfermedades oculares que cursan con estrés oxidativo, o como coadyuvante de otros tratamientos actuales existentes, así como en tratamientos post-operatorios para tratar y/o prevenir reacciones adversas inflamatorias o de estrés oxidativo.[FR] La présente invention se rapporte à la composition qui contient une enzyme appartenant au groupe des superoxyde dismutases (SOD) ou bien n'importe quel mimétique de la SOD et similaires conjointement à l'acide hyaluronique et EDTA. Ladite composition fait partie d'une formulation pharmaceutique qui favorise ou maintient la santé oculaire par l'inhibition des dommages cellulaire et tissulaire produits par les radicaux libres et qui est utile dans le traitement et/ou la prévention de maladies oculaires qui sont associées au stress oxydatif ou comme co-adjuvant d'autres traitements actuels existants, ainsi que dans des traitements post-opératoires pour traiter et/ou prévenir des réactions indésirables inflammatoires ou de stress oxydatif.Peer reviewedFundación para el fomento de la investigación sanitaria y biomédica de la Comunidad Valenciana (FISABIO), Universitat Politècnica de València, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Cardenal Herrera CEU San Pablo, Universitat de ValènciaA1 Solicitud de patente con informe sobre el estado de la técnic

Active and Regioselective Ru Single-Site Heterogeneous Catalysts for Alpha-Olefin Hydroformylation

A heterogeneous ruthenium catalyst consisting of isolated single atoms and disordered clusters stabilized in a N-doped carbon matrix has been synthesized with very good activity and remarkable regioselectivity in the hydroformylation of 1-hexene. The role of the nitrogen heteroatoms has been probed essential to increase the catalyst stability and activity, enabling the stabilization of Ru(II)-N sites according to X-ray photoelectron spectroscopy (XPS) and XANES. Intrinsic size-dependent activity of Ru species of different atomicity has been extracted, correlating the observed reaction rate and the particle size distribution determined by means of aberration-corrected high-angle annular dark-field scanning transmission electron microscopy, permitting the identification of single-atom sites as the most active ones. This catalyst appears as a promising alternative with respect to its heterogeneous counterparts, paving the way for designing improved Ru heterogeneous catalysts.The research leading to these results has received funding from the Spanish Ministry of Science, Innovation and Universities, through the “Severo Ochoa” Excellence Programme (SEV-2016-0683) and RTI2018-099668-B-C21 and PGC2018-101247-B-100 “Programa Estatal de Generación de Conocimiento”. P.C acknowledges the financial support from the “Generalitat Valenciana” through the project AICO/2020/205. HR-HAADF-STEM measurements were performed at the DME-UCA node of ELECMI ICTS with financial support from FEDER/MINECO (MAT2017-87579-R and PID2019-110018GA-I00); XAS experiments were performed at the BL22-CLÆSS beamline at the ALBA Synchrotron with the collaboration of ALBA staff as part of projects 2019093692 and 2020024106. XPS experiments were performed at the BL24-CIRCE beamline at the ALBA Synchrotron with the collaboration of ALBA staff. J.E.B acknowledges the Polytechnical University of Valencia for the economic support through the grant of an FPI scholarship associated with the PAID programme “Programa de Ayudas de Investigación y Desarrollo”

Bifunctional atomically dispersed ruthenium electrocatalysts for efficient bipolar membrane water electrolysis

Atomically dispersed catalysts (ADCs) have recently drawn considerable interest for use in water electrolysis to produce hydrogen, because they allow for maximal utilization of metal species, particularly the expensive and scarce platinum group metals. Herein, we report the electrocatalytic performance of atomically dispersed ruthenium catalysts (Ru ADCs) with ultralow Ru loading (0.2 wt%). The as-obtained Ru ADCs (Ru (0.2)-NC) are active for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), which only require a low overpotential (η) of 47.1 and 72.8 mV to deliver 10 mA cm−2 for HER in 0.5 M H2SO4 and 1.0 M KOH, respectively, and of 300 mV for OER in 1.0 M KOH, showing favorable bifunctionality. Density functional theory (DFT) calculations reveal that the Ru–N bonding plays an important role in lowering the energy barrier of the reactions, boosting the HER and OER activities. Furthermore, the bipolar membrane (BPM) water electrolysis using the bifunctional Ru (0.2)-NC as both HER and OER catalysts can afford 10 mA cm−2 under a low cell voltage of only 0.89 V, and does not show any performance decay upon 100 h continuous operation, showing great potential for energy-saving hydrogen production.info:eu-repo/semantics/publishedVersio