Readily available Ti-beta as an efficient catalyst for greener and sustainable production of campholenic aldehyde

[EN] Different Ti-beta zeolite samples were prepared following a convenient and optimized post-synthetic route and starting from commercial Al-beta zeolite. Lewis acid sites have been successfully incorporated into vacant tetrahedral (T)-sites of a dealuminated beta-framework by ball-milling solid-state ion-exchange. A tribology-ball milling process was used in order to increase the interaction between dealuminated-beta zeolite and the Ti-precursor. Thermal treatments with water and aqueous solution of NaNO or Li NO allowed optimization of the catalytic properties of the Ti-Lewis active sites which exhibited excellent catalytic activity and stability for the isomerization of ¿-pinene oxide into campholenic aldehyde in both batch and fixed bed reactor systems. Additionally, the catalytic performance of the post-synthesised Ti-beta zeolite was compared to a Ti-beta zeolite prepared in fluoride media. From different points of view such as preparation of readily, highly active, selective and stable catalysts, throughput, sustainability and cost, herein we report the selective solid catalysed ¿-PO isomerization with excellent results, 88% selectivity and yield, a CA production of 225 g g h and new opportunities.The authors are grateful for financial support from the Spanish Government by MAT2017-82288-C2-1-P and Severo Ochoa Excellence Program SEV-2016-0683. The contribution of Mr. Pablo Ramos to the experimental work is also gratefully acknowledged.Puche Panadero, M.; Velty, A. (2019). Readily available Ti-beta as an efficient catalyst for greener and sustainable production of campholenic aldehyde. Catalysis Science & Technology. 9(16):4293-4303. https://doi.org/10.1039/c9cy00957dS42934303916Stekrova, M., Kumar, N., Aho, A., Sinev, I., Grünert, W., Dahl, J., … Murzin, D. Y. (2014). Isomerization of α-pinene oxide using Fe-supported catalysts: Selective synthesis of campholenic aldehyde. Applied Catalysis A: General, 470, 162-176. doi:10.1016/j.apcata.2013.10.044Kunkeler, P. J., van der Waal, J. C., Bremmer, J., Zuurdeeg, B. J., Downing, R. S., & van Bekkum, H. (1998). Catalysis Letters, 53(1/2), 135-138. doi:10.1023/a:1019049704709Pitínová-Štekrová, M., Eliášová, P., Weissenberger, T., Shamzhy, M., Musilová, Z., & Čejka, J. (2018). Highly selective synthesis of campholenic aldehyde over Ti-MWW catalysts by α-pinene oxide isomerization. Catalysis Science & Technology, 8(18), 4690-4701. doi:10.1039/c8cy01231hArbusow, B. (1935). Studium der Isomerisation von Terpen-oxyden, I. Mitteil.: Isomerisation des α-Pinen-oxydes bei der Reaktion von Reformatsky. Berichte der deutschen chemischen Gesellschaft (A and B Series), 68(8), 1430-1435. doi:10.1002/cber.19350680803Arata, K., & Tanabe, K. (1979). ISOMERIZATION OF α-PlNENE OXIDE OVER SOLID ACIDS AND BASES. Chemistry Letters, 8(8), 1017-1018. doi:10.1246/cl.1979.1017Kaminska, J., Schwegler, M. A., Hoefnagel, A. J., & van Bekkum, H. (1992). The isomerization of α-pinene oxide with Brønsted and Lewis acids. Recueil des Travaux Chimiques des Pays-Bas, 111(10), 432-437. doi:10.1002/recl.19921111004Huybrechts, D. R. C., Bruycker, L. D., & Jacobs, P. A. (1990). Oxyfunctionalization of alkanes with hydrogen peroxide on titanium silicalite. Nature, 345(6272), 240-242. doi:10.1038/345240a0C. Ferrini and H. W.Kouwenhoven , New Developments in Selective Oxidation , ed. G. Centi and F. Trifiro , Elsevier , Amsterdam , 1990 , p. 53Camblor, M. A., Costantini, M., Corma, A., Gilbert, L., Esteve, P., Martínez, A., & Valencia, S. (1996). Synthesis and catalytic activity of aluminium-free zeolite Ti-β oxidation catalysts. Chem. Commun., (11), 1339-1340. doi:10.1039/cc9960001339Blasco, T., Camblor, M. A., Corma, A., Esteve, P., Martínez, A., Prieto, C., & Valencia, S. (1996). Unseeded synthesis of Al-free Ti-β zeolite in fluoride medium: a hydrophobic selective oxidation catalyst. Chem. Commun., (20), 2367-2368. doi:10.1039/cc9960002367Li, P., Liu, G., Wu, H., Liu, Y., Jiang, J., & Wu, P. (2011). Postsynthesis and Selective Oxidation Properties of Nanosized Sn-Beta Zeolite. The Journal of Physical Chemistry C, 115(9), 3663-3670. doi:10.1021/jp1076966Dijkmans, J., Gabriëls, D., Dusselier, M., de Clippel, F., Vanelderen, P., Houthoofd, K., … Sels, B. F. (2013). Productive sugar isomerization with highly active Sn in dealuminated β zeolites. Green Chemistry, 15(10), 2777. doi:10.1039/c3gc41239cHammond, C., Conrad, S., & Hermans, I. (2012). Simple and Scalable Preparation of Highly Active Lewis Acidic Sn-β. Angewandte Chemie International Edition, 51(47), 11736-11739. doi:10.1002/anie.201206193Wolf, P., Hammond, C., Conrad, S., & Hermans, I. (2014). Post-synthetic preparation of Sn-, Ti- and Zr-beta: a facile route to water tolerant, highly active Lewis acidic zeolites. Dalton Transactions, 43(11), 4514. doi:10.1039/c3dt52972jTolborg, S., Sádaba, I., Osmundsen, C. M., Fristrup, P., Holm, M. S., & Taarning, E. (2015). Tin-containing Silicates: Alkali Salts Improve Methyl Lactate Yield from Sugars. ChemSusChem, 8(4), 613-617. doi:10.1002/cssc.201403057Camblor, M. A., Corma, A., & Pérez-Pariente, J. (1993). Synthesis of titanoaluminosilicates isomorphous to zeolite Beta, active as oxidation catalysts. Zeolites, 13(2), 82-87. doi:10.1016/0144-2449(93)90064-aGarcia Vargas, N., Stevenson, S., & Shantz, D. F. (2012). Synthesis and characterization of tin(IV) MFI: Sodium inhibits the synthesis of phase pure materials. Microporous and Mesoporous Materials, 152, 37-49. doi:10.1016/j.micromeso.2011.11.036Tatsumi, T., Koyano, K. A., & Shimizu, Y. (2000). Effect of potassium on the catalytic activity of TS-1. Applied Catalysis A: General, 200(1-2), 125-134. doi:10.1016/s0926-860x(00)00630-xKhouw, C. B., & Davis, M. E. (1995). Catalytic Activity of Titanium Silicates Synthesized in the Presence of Alkali-Metal and Alkaline-Earth Ions. Journal of Catalysis, 151(1), 77-86. doi:10.1006/jcat.1995.1010Kuwahara, Y., Nishizawa, K., Nakajima, T., Kamegawa, T., Mori, K., & Yamashita, H. (2011). Enhanced Catalytic Activity on Titanosilicate Molecular Sieves Controlled by Cation−π Interactions. Journal of the American Chemical Society, 133(32), 12462-12465. doi:10.1021/ja205699dTaarning, E., Saravanamurugan, S., Spangsberg Holm, M., Xiong, J., West, R. M., & Christensen, C. H. (2009). Zeolite-Catalyzed Isomerization of Triose Sugars. ChemSusChem, 2(7), 625-627. doi:10.1002/cssc.200900099Bermejo-Deval, R., Orazov, M., Gounder, R., Hwang, S.-J., & Davis, M. E. (2014). Active Sites in Sn-Beta for Glucose Isomerization to Fructose and Epimerization to Mannose. ACS Catalysis, 4(7), 2288-2297. doi:10.1021/cs500466jBlasco, T., Camblor, M. A., Corma, A., Esteve, P., Guil, J. M., Martínez, A., … Valencia, S. (1998). Direct Synthesis and Characterization of Hydrophobic Aluminum-Free Ti−Beta Zeolite. The Journal of Physical Chemistry B, 102(1), 75-88. doi:10.1021/jp973288wR. K. Iler , The Chemistry of Silica , Wiley , New York , 1979Cordon, M. J., Harris, J. W., Vega-Vila, J. C., Bates, J. S., Kaur, S., Gupta, M., … Gounder, R. (2018). Dominant Role of Entropy in Stabilizing Sugar Isomerization Transition States within Hydrophobic Zeolite Pores. Journal of the American Chemical Society, 140(43), 14244-14266. doi:10.1021/jacs.8b08336BORONAT, M., CONCEPCION, P., CORMA, A., RENZ, M., & VALENCIA, S. (2005). Determination of the catalytically active oxidation Lewis acid sites in Sn-beta zeolites, and their optimisation by the combination of theoretical and experimental studies. Journal of Catalysis, 234(1), 111-118. doi:10.1016/j.jcat.2005.05.023Gleeson, D., Sankar, G., Richard A. Catlow, C., Meurig Thomas, J., Spanó, G., Bordiga, S., … Lamberti, C. (2000). The architecture of catalytically active centers in titanosilicate (TS-1) and related selective-oxidation catalysts. Physical Chemistry Chemical Physics, 2(20), 4812-4817. doi:10.1039/b005780kOtomo, R., Kosugi, R., Kamiya, Y., Tatsumi, T., & Yokoi, T. (2016). Modification of Sn-Beta zeolite: characterization of acidic/basic properties and catalytic performance in Baeyer–Villiger oxidation. Catalysis Science & Technology, 6(8), 2787-2795. doi:10.1039/c6cy00532bImamura, S., Nakai, T., Kanai, H., & Ito, T. (1995). Effect of tetrahedral Ti in titania–silica mixed oxides on epoxidation activity and Lewis acidity. J. Chem. Soc., Faraday Trans., 91(8), 1261-1266. doi:10.1039/ft9959101261Yang, G., & Zhou, L. (2017). Active Sites of M(IV)-incorporated Zeolites (M = Sn, Ti, Ge, Zr). Scientific Reports, 7(1). doi:10.1038/s41598-017-16409-yAlaerts, L., Séguin, E., Poelman, H., Thibault-Starzyk, F., Jacobs, P. A., & De Vos, D. E. (2006). Probing the Lewis Acidity and Catalytic Activity of the Metal–Organic Framework [Cu3(btc)2] (BTC=Benzene-1,3,5-tricarboxylate). Chemistry - A European Journal, 12(28), 7353-7363. doi:10.1002/chem.20060022

Nanomateriales híbridos basados en complejos de metales de transición anclados sobre óxido de grafeno. Aplicaciones catalíticas

Graphene-based hybrid materials and transition metal complexes play an important role in the science of materials and catalysis, as well as in other technological fields, as highlighted in the literature. In this doctoral thesis new hybrid nanomaterials based on different transition metal complexes (mono- and multimetallic) anchored on the surface of graphene oxide or graphene oxide modified with organic groups have been developed. This doctoral memory constitutes a "classic" work from the point of view of content structure, which are distributed over seven chapters. In the first chapter, the general considerations and applications of graphene and associated hybrid materials are presented together with a classification of strategies of synthesis and chemical structure of graphene oxides under study. Next, the second chapter addresses the objectives of this research work focused on the study of hybrid nanomaterials based on transition metals and graphene. The third and fourth chapter focuses on the synthesis of delaminated graphene oxide by modifying the conventional Hummers method, which provides the laminar support on which donor oxygen and nitrogen groups are covalently anchored. These groups allow the coordinating or axial immobilization of a chiral Mn (III) -salen complex, to provide hybrid nanocatalysts directed to the enantioselective epoxidation of prochiral alkenes. In the fifth chapter of this specification, the chemical modification of graphene oxide is described by amidation and acylation reactions of the carboxylic groups and by the covalent anchoring of a ruthenium (II) organometallic complex. Hybrid nanomaterials are studied in the catalytic racemization of (S) -1-phenylethanol, and the multifunctional enzyme catalyst (CALB)-Ru-OG in the kinetic resolution of 1- phenylethanol. The sixth chapter focuses on the coordinating immobilization of hexanuclear molybdenum (II) nanoclusters with halogens in graphene oxide to provide nanohybrids that have been investigated in the field of photocatalysis and whose activity has been compared with that obtained under homogeneous conditions. Specifically, photoreduction of H2O to H2 and photooxidation of certain organic substrates has been approached, taking advantage of the photoluminescent properties of the molybdenum (II) clusters and the electronic properties of the graphite materials. The characterization of the molecular complexes and nanomaterials synthesized throughout chapters 3-6 of the present thesis is carried out using chemical and structural analysis techniques and spectroscopic, chromatographic, surface and image techniques. The last chapter, and not the least important, highlights the conclusions obtained in this research.Los materiales híbridos basados en grafeno y complejos de metales de transición juegan un papel importante en la ciencia de materiales y catálisis, así como en otros campos tecnológicos, según se destaca en la literatura. En esta tesis doctoral se han desarrollado nuevos nanomateriales híbridos basados en complejos metálicos de transición de diferente índole (mono- y multimetálicos) anclados en la superficie del óxido de grafeno u óxido de grafeno modificado con grupos orgánicos. Esta memoria doctoral constituye un trabajo "clásico" desde el punto de vista de estructura de contenidos, los cuales se distribuyen a lo largo de siete capítulos. En el primer capítulo, se exponen las consideraciones generales y aplicaciones de los grafenos y de los materiales híbridos asociados, junto con una clasificación de estrategias de síntesis y estructura química de los óxidos de grafeno objeto de estudio. A continuación, el capítulo segundo aborda los objetivos del presente trabajo de investigación centrados en el estudio de nanomateriales híbridos basados en metales de transición y grafenos. El tercer y cuarto capítulo se centran en la síntesis de óxido de grafeno deslaminado modificando el método de Hummers convencional, que proporciona el soporte laminar sobre el que se anclan covalentemente grupos oxígeno y nitrógeno dadores. Estos grupos permiten la inmovilización coordinativa o axial de un complejo de Mn (III)-salen quiral, para proporcionar nanocatalizadores híbridos dirigidos a la epoxidación enantioselectiva de alquenos proquirales. En el quinto capítulo de esta memoria, se describe la modificación química del óxido de grafeno mediante reacciones de amidación y de acilación de los grupos carboxílicos, y mediante el anclaje covalente de un complejo organometálico de rutenio (II). Los nanomateriales híbridos se estudian en la racemización catalítica del (S)-1-feniletanol, y el catalizador multifuncional enzima (CALB)-Ru-OG en la resolución cinética del 1-feniletanol. El sexto capítulo, se centra en la inmovilización coordinativa de nanoclústeres hexanucleares de haluros de molibdeno (II) en óxido de grafeno, para proporcionar nanohíbridos que se han investigado en el campo de la fotocatálisis y cuya actividad se ha comparado con la obtenida en condiciones homogéneas. Concretamente, se ha abordado la fotorreducción de H2O a H2 y la fotooxidación de determinados sustratos orgánicos, aprovechando las propiedades fotoluminiscentes de los clústeres de molibdeno (II) y las propiedades electrónicas de los materiales grafénicos. La caracterización de los complejos moleculares y de los nanomateriales sintetizados a lo largo de los capítulos 3-6 de la presente tesis se lleva a cabo, mediante técnicas de análisis químico y estructural, espectroscópicas, cromatográficas, de superficie y de imagen El último capítulo y no por ello el menos importante, destaca las conclusiones obtenidas en este trabajo de investigación.Els materials híbrids basats en grafè i complexos de metalls de transició juguen un paper important en la ciència de materials i catàlisi, així com en altres camps tecnològics, segons es destaca en la literatura. En aquesta tesi doctoral s'han desenvolupat nous nanomaterials híbrids basats en complexos metàl·lics de transició de diferent índole (mono- i multimetálicos) ancorats en la superfície de l'òxid de grafè o òxid de grafè modificat amb grups orgànics. Aquesta memòria doctoral constitueix un treball "clàssic" des del punt de vista d'estructura de continguts, els quals es distribueixen al llarg de set capítols. En el primer capítol, s'exposen les consideracions generals i aplicacions dels grafenos i dels materials híbrids associats, juntament amb una classificació d'estratègies de síntesi i estructura química dels òxids de grafè objecte d'estudi. A continuació, el capítol segon aborda els objectius del present treball d'investigació centrats en l'estudi de nanomaterials híbrids basats en metalls de transició i grafenos. El tercer i quart capítol se centren en la síntesi d'òxid de grafè deslaminat modificant el mètode de Hummers convencional, que proporciona el suport laminar sobre el qual s'ancoren covalentment grups oxigen i nitrogen donadors. Aquests grups permeten la immobilització coordinativa o axial d'un complex de Mn (III) -salen quiral, per proporcionar nanocatalitzadors híbrids dirigits a l'epoxidació enantioselectiva d'alquens proquirals. En el cinquè capítol d'aquesta memòria, es descriu la modificació química de l'òxid de grafè mitjançant reaccions de amidació i de acilació dels grups carboxílics, i mitjançant l'ancoratge covalent d'un complex organometàl·lic de ruteni (II). Els nanomaterials híbrids s'estudien a la racemització catalítica del (S) -1-feniletanol, i el catalitzador multifuncional enzim (CALB)-Ru-OG en la resolució cinètica de l'1-feniletanol. El sisè capítol, es centra en la immobilització coordinativa de nanoclústeres hexanuclears de molibdè (II) amb halògens en òxid de grafè, per proporcionar nanohíbrids que s'han investigat en el camp de la fotocatàlisi i l'activitat s'ha comparat amb l'obtinguda en condicions homogènies. Concretament, s'ha abordat la fotoreducció d'H2O a H2 i la fotooxidació de determinats substrats orgànics, aprofitant les propietats fotoluminiscents dels clústers de molibdè (II) i les propietats electròniques dels materials grafénics. La caracterització dels complexos moleculars i dels nanomaterials sintetitzats al llarg dels capítols 3-6 de la present tesi es du a terme, mitjançant tècniques d'anàlisi química i estructural, espectroscòpiques, cromatogràfiques, de superfície i d'imatge. L'últim capítol i no per això menys important, destaca les conclusions obtingudes en aquest treball de recerca.Puche Panadero, M. (2017). Nanomateriales híbridos basados en complejos de metales de transición anclados sobre óxido de grafeno. Aplicaciones catalíticas [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/86211TESI

A spectroscopic study to assess the photogeneration of singlet oxygen by graphene oxide

[EN] The photogeneration of singlet oxygen (O-1(2) ) during short irradiation times of graphene oxide (GO) is assessed under visible light with soft irradiation conditions either directly monitoring the phosphorescence emission of O-1(2) at ca. 1275 nm, or indirectly by means of the fluorescent probe 9, 10-anthracene diyl-bis(methylene)dimalonic acid (ABDA). Results obtained using both methodologies lead to the conclusion that O-1(2) generation is negligible under our experimental conditions. In the case of using ABDA very small emission changes were recorded, which could be attributed to other side reactions. Special care should be taken when using this spectroscopic probe to assess the generation of O-1(2), since ABDA and related probes based on the reactivity of the anthracene fluorophore can also detect electron transfer processes. This kind of approaches have been less explored in the field of Materials Science at the nanoscale, and we believe that the knowledge on the lack of generation of O-1(2) by irradiated GO is informative and useful, especially for the assessment of the environmental and biological toxicity of nanomaterials based on GO. (C) 2019 Elsevier B.V. All rights reserved.Ministerio de Economia y Competitividad of Spain (grant CTQ2015-71004-R) and Universitat Jaume I (grant P1.1B2015-76) are thanked for their financial support. C.F-L. thanks the Ministerio de Economia y Competitividad of Spain for a FPI fellowship. Technical support from SCIC of University Jaume I is acknowledged. The Instituto de Tecnologia Quimica (ITQ) thanks the support of the Severo Ochoa Program (SEV-2016-0683), and Consejo Superior de Investigaciones Cientificas (I-Link1063). We would like to thank Dr. Francisco Bosca for his technical assistance with the singlet oxygen emission measurements at the ITQ.Felip-León, C.; Puche Panadero, M.; Miravet, JF.; Galindo, F.; Feliz Rodriguez, M. (2019). A spectroscopic study to assess the photogeneration of singlet oxygen by graphene oxide. Materials Letters. 251:45-51. https://doi.org/10.1016/j.matlet.2019.05.001S455125

Nanostructured Hybrids Based on Tantalum Bromide Octahedral Clusters and Graphene Oxide for Photocatalytic Hydrogen Evolution

[EN] The generation of hydrogen (H2) using sunlight has become an essential energy alternative for decarbonization. The need for functional nanohybrid materials based on photo- and electroactive materials and accessible raw materials is high in the field of solar fuels. To reach this goal, single-step synthesis of {Ta6Bri12}@GO (GO = graphene oxide) nanohybrids was developed by immobilization of [{Ta6Bri12}Bra2(H2O)a4]·4H2O (i = inner and a = apical positions of the Ta6 octahedron) on GO nanosheets by taking the advantage of the easy ligand exchange of the apical cluster ligands with the oxygen functionalities of GO. The nanohybrids were characterized by spectroscopic, analytical, and morphological techniques. The hybrid formation enhances the yield of photocatalytic H2 from water with respect to their precursors and this is without the presence of precious metals. This enhancement is attributed to the optimal cluster loading onto the GO support and the crucial role of GO in the electron transfer from Ta6 clusters into GO sheets, thus suppressing the charge recombination. In view of the simplicity and versatility of the designed photocatalytic system, octahedral tantalum clusters are promising candidates to develop new and environmentally friendly photocatalysts for H2 evolution.This research was funded by Ministerio de Ciencia e Innovación (MICINN), grant number PGC2018-099744. Parts of this research dealing with metal cluster synthesis and characterization received funding from project RTI2018-096399-A-I00 funded by MCIN/AEI/10.13039/501100011033/ and ¿ERDF A way of making Europe¿. J.S.H. gratefully acknowledges the Consejo Superior de Investigaciones Científicas (CSIC) and Generalitat Valenciana (GVA), Programa Santiago Grisolía, grant number GRISOLIA/2021/054. M.S. received financial support by the Russian Foundation for Basic Research (grant number 20-33-90010) and the Ministry of Science and Higher Education of the Russian Federation (grant number 121031700313¿8). The APC was funded by this journal.Hernandez-Niño, JS.; Shamsurin, M.; Puche Panadero, M.; Sokolov, MN.; Feliz Rodriguez, M. (2022). Nanostructured Hybrids Based on Tantalum Bromide Octahedral Clusters and Graphene Oxide for Photocatalytic Hydrogen Evolution. Nanomaterials. 12(20). https://doi.org/10.3390/nano12203647122

Un periodismo sin periodos: actualidad y tiempo en la era digital

La actualidad es –junto con el interés– uno de los criterios de selección de los acontecimientos que serán convertidos en noticia. De ordinario se interpreta este factor en relación al tiempo presente cronológico y a la eficacia de los medios de comunicación para reducir el tiempo que transcurre entre un hecho y su difusión y conocimiento público. La capacidad de las actuales tecnologías de la comunicación para registrar en tiempo real los acontecimientos y ponerlos inmediatamente a disposición de un público mundial a través de Internet, junto con la ubicuidad del consumo a través de múltiples dispositivos, hace necesaria una reflexión acerca de la vigencia de algunos de los paradigmas hasta ahora aceptados. La investigación en comunicación se ha desarrollado bajo dos paradigmas distintos: el de la transmisión y el de la integración. En el primero, relacionado tradicionalmente con la noción de actualidad, explica la comunicación desde los medios y la eficacia de los procesos para transmitir un contenido. El segundo entiende la comunicación como la integración social que crea una comunidad. Ante los cambios que los nuevos medios introducen en el papel del tiempo en el periodismo, ¿hasta qué punto puede sostenerse el criterio de actualidad en su relación con el presente cronológico? ¿Qué implica esto para los diarios impresos? El objetivo de este trabajo es explorar el criterio de actualidad desde el paradigma de la comunicación como integración social, abriéndolo a otras dimensiones, que demuestran la verdadera vigencia del periodismo hoy. El trabajo aborda dos cuestiones: una revisión el criterio de actualidad apoyándonos en la diferencia entre el tiempo cronológico y el tiempo interior; y la relación de esta dimensión temporal de la actualidad con los efectos de integración y cohesión social que genera. Concluimos señalando en qué sentido el criterio de actualidad sigue siendo hoy día relevante

Uniform Ru nanoparticles on N-doped graphene for selective hydrogenation of fatty acids to alcohols

[EN] Ruthenium nanoparticles (Ru NPs) supported on reduced-graphene oxide doped with N (NH2-rGO) was synthesized and used for the selective hydrogenation of fatty acids to alcohols, being the hydrogenation of palmitic acid selected as model. Ru was stabilized forming uniform nanometer size particles on N-doped graphene (Ru/NH2-rGO). The resultant catalyst was very selective for the carbonyl reduction giving 93% of the aliphatic alcohol at 99% conversion. The Ru/NH2-rGO catalysts was more active and selective than the corresponding Ru on non-doped graphene (Ru/rGO) or Ru on carbon (Ru/C). Mechanistic studies points to a dual mechanism for H-2 dissociation, i.e. homolytic and heterolytic cleavage exists on the Ru/NH2-rGO, while only the homolytic H-2 dissociation occurs on Ru/rGO. This heterolytic splitting, which activates the carbonyl groups and facilitates the hydrogenation of aliphatic acids, is due to the presence of basic centres next to the Ru atoms. The presence of N atoms also increases the stability of the catalyst, allowing a reuse up to four times. (C) 2019 Elsevier Inc. All rights reserved.The authors thank Institute de Tecnologia Quimica (ITQ), Consejo Superior de Investigaciones Cientificas (CSIC) and Universitat Politecnica de Valencia (UPV) for the facilities and Severo Ochoa excellence programme, "Juan de la Cierva" programme and Primeros Proyectos de Investigacion (PAID-06-18) for financial support. We gratefully acknowledge Prof. A. Corma for his invaluable contribution to this research. We also thank the Electron Microscopy Service of the UPV for TEM facilities, Jose A. Vidal-Moya (ITQ CSIC-UPV) for NMR measurements and J. Gaona and C. Morales for their assistance in catalytic reactions.Martínez-Prieto, LM.; Puche Panadero, M.; Cerezo-Navarrete, C.; Chaudret, B. (2019). Uniform Ru nanoparticles on N-doped graphene for selective hydrogenation of fatty acids to alcohols. Journal of Catalysis. 377:429-437. https://doi.org/10.1016/j.jcat.2019.07.040S42943737

Chemical Modification of Microcin J25 Reveals New Insights on the Stereospecific Requirements for Antimicrobial Activity

In this study, microcin J25, a potent antimicrobial lasso peptide that acts on Gram-negative bacteria, was subjected to a harsh treatment with a base in order to interrogate its stability and mechanism of action and explore its structure-activity relationship. Despite the high stability reported for this lasso peptide, the chemical treatment led to the detection of a new product. Structural studies revealed that this product retained the lasso topology, but showed no antimicrobial activity due to the epimerization of a key residue for the activity. Further microbiological assays also demonstrated that it showed a high synergistic effect with colistin

Polyvinylidene Fluoride-Graphene Oxide Membranes for Dye Removal under Visible Light Irradiation

[EN] In this study, polyvinylidene fluoride (PVDF)-graphene oxide (GO) membranes were obtained by employing triethyl phosphate (TEP) as a solvent. GO nanosheets were prepared and characterized in terms of scanning and transmission electron microscopy (SEM and TEM, respectively), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), chemical analysis and inductively coupled plasma mass spectroscopy (ICP). Two different phase inversion techniques, Non-Solvent Induced Phase Separation (NIPS) and Vapour-Induced Phase Separation (VIPS)/NIPS, were applied to study the effect of fabrication procedure on the membrane structure and properties. Membranes were characterized by SEM, AFM, pore size, porosity, contact angle and mechanical tests, and finally tested for photocatalytic methylene blue (MB+) degradation under visible light irradiation. The effect of different pH values of dye aqueous solutions on the photocatalytic efficiency was investigated. Finally, the influence of NaCl salt on the MB+ photodegradation process was also evaluated.The authors acknowledge the financial support from Iran Science Ministry. The authors also sincerely thank the Institute on Membrane Technology, National Research Council of Italy (ITM-CNR) for kindly collaborate.Alyarnezhad, S.; Marino, T.; Parsa, JB.; Galiano, F.; Ursino, C.; García Gómez, H.; Puche, M.... (2020). Polyvinylidene Fluoride-Graphene Oxide Membranes for Dye Removal under Visible Light Irradiation. E-Polymers. 12(7):1-19. https://doi.org/10.3390/polym12071509S119127Figoli, A., Ursino, C., Galiano, F., Di Nicolò, E., Campanelli, P., Carnevale, M. C., & Criscuoli, A. (2017). Innovative hydrophobic coating of perfluoropolyether (PFPE) on commercial hydrophilic membranes for DCMD application. Journal of Membrane Science, 522, 192-201. doi:10.1016/j.memsci.2016.08.066Dao, V.-D., Vu, N. H., & Choi, H.-S. (2020). All day Limnobium laevigatum inspired nanogenerator self-driven via water evaporation. Journal of Power Sources, 448, 227388. doi:10.1016/j.jpowsour.2019.227388Dao, V.-D., Vu, N. H., & Yun, S. (2020). Recent advances and challenges for solar-driven water evaporation system toward applications. Nano Energy, 68, 104324. doi:10.1016/j.nanoen.2019.104324Dao, V.-D., & Choi, H.-S. (2018). Carbon-Based Sunlight Absorbers in Solar-Driven Steam Generation Devices. Global Challenges, 2(2), 1700094. doi:10.1002/gch2.201700094Pastrana-Martínez, L. M., Morales-Torres, S., Figueiredo, J. L., Faria, J. L., & Silva, A. M. T. (2015). Graphene oxide based ultrafiltration membranes for photocatalytic degradation of organic pollutants in salty water. Water Research, 77, 179-190. doi:10.1016/j.watres.2015.03.014Zhang, X., Wang, D. K., & Diniz da Costa, J. C. (2014). Recent progresses on fabrication of photocatalytic membranes for water treatment. Catalysis Today, 230, 47-54. doi:10.1016/j.cattod.2013.11.019Athanasekou, C. P., Moustakas, N. G., Morales-Torres, S., Pastrana-Martínez, L. M., Figueiredo, J. L., Faria, J. L., … Falaras, P. (2015). Ceramic photocatalytic membranes for water filtration under UV and visible light. Applied Catalysis B: Environmental, 178, 12-19. doi:10.1016/j.apcatb.2014.11.021Athanasekou, C. P., Romanos, G. E., Katsaros, F. K., Kordatos, K., Likodimos, V., & Falaras, P. (2012). Very efficient composite titania membranes in hybrid ultrafiltration/photocatalysis water treatment processes. Journal of Membrane Science, 392-393, 192-203. doi:10.1016/j.memsci.2011.12.028Romanos, G. E., Athanasekou, C. P., Katsaros, F. K., Kanellopoulos, N. K., Dionysiou, D. D., Likodimos, V., & Falaras, P. (2012). Double-side active TiO2-modified nanofiltration membranes in continuous flow photocatalytic reactors for effective water purification. Journal of Hazardous Materials, 211-212, 304-316. doi:10.1016/j.jhazmat.2011.09.081Zhang, W., Dong, F., Xiong, T., & Zhang, Q. (2014). Synthesis of BiOBr–graphene and BiOBr–graphene oxide nanocomposites with enhanced visible light photocatalytic performance. Ceramics International, 40(7), 9003-9008. doi:10.1016/j.ceramint.2014.01.112Dadvar, E., Kalantary, R. R., Ahmad Panahi, H., & Peyravi, M. (2017). Efficiency of Polymeric Membrane Graphene Oxide-TiO2for Removal of Azo Dye. Journal of Chemistry, 2017, 1-13. doi:10.1155/2017/6217987Simone, S., Galiano, F., Faccini, M., Boerrigter, M., Chaumette, C., Drioli, E., & Figoli, A. (2017). Preparation and Characterization of Polymeric-Hybrid PES/TiO2 Hollow Fiber Membranes for Potential Applications in Water Treatment. Fibers, 5(2), 14. doi:10.3390/fib5020014Liu, G., Han, K., Ye, H., Zhu, C., Gao, Y., Liu, Y., & Zhou, Y. (2017). Graphene oxide/triethanolamine modified titanate nanowires as photocatalytic membrane for water treatment. Chemical Engineering Journal, 320, 74-80. doi:10.1016/j.cej.2017.03.024Djafer, L., Ayral, A., & Ouagued, A. (2010). Robust synthesis and performance of a titania-based ultrafiltration membrane with photocatalytic properties. Separation and Purification Technology, 75(2), 198-203. doi:10.1016/j.seppur.2010.08.001Jung, J.-T., Lee, W.-H., & Kim, J.-O. (2016). Photodegradation and permeability of conventional photocatalytic reactor and two different submerged membrane photocatalytic reactors for the removal of humic acid in water. Desalination and Water Treatment, 57(55), 26765-26772. doi:10.1080/19443994.2016.1189700Xu, Z., Wu, T., Shi, J., Teng, K., Wang, W., Ma, M., … Fan, J. (2016). Photocatalytic antifouling PVDF ultrafiltration membranes based on synergy of graphene oxide and TiO2 for water treatment. Journal of Membrane Science, 520, 281-293. doi:10.1016/j.memsci.2016.07.060Gao, Y., Hu, M., & Mi, B. (2014). Membrane surface modification with TiO2–graphene oxide for enhanced photocatalytic performance. Journal of Membrane Science, 455, 349-356. doi:10.1016/j.memsci.2014.01.011Zhao, H., Chen, S., Quan, X., Yu, H., & Zhao, H. (2016). Integration of microfiltration and visible-light-driven photocatalysis on g-C 3 N 4 nanosheet/reduced graphene oxide membrane for enhanced water treatment. Applied Catalysis B: Environmental, 194, 134-140. doi:10.1016/j.apcatb.2016.04.042Cruz-Ortiz, B. R., Hamilton, J. W. J., Pablos, C., Díaz-Jiménez, L., Cortés-Hernández, D. A., Sharma, P. K., … Byrne, J. A. (2017). Mechanism of photocatalytic disinfection using titania-graphene composites under UV and visible irradiation. Chemical Engineering Journal, 316, 179-186. doi:10.1016/j.cej.2017.01.094Galiano, F., Song, X., Marino, T., Boerrigter, M., Saoncella, O., Simone, S., … Figoli, A. (2018). Novel Photocatalytic PVDF/Nano-TiO2 Hollow Fibers for Environmental Remediation. Polymers, 10(10), 1134. doi:10.3390/polym10101134Szymański, K., Morawski, A. W., & Mozia, S. (2016). Humic acids removal in a photocatalytic membrane reactor with a ceramic UF membrane. Chemical Engineering Journal, 305, 19-27. doi:10.1016/j.cej.2015.10.024Marino, T., Blefari, S., Di Nicolò, E., & Figoli, A. (2017). A more sustainable membrane preparation using triethyl phosphate as solvent. Green Processing and Synthesis, 6(3). doi:10.1515/gps-2016-0165Benhabiles, O., Galiano, F., Marino, T., Mahmoudi, H., Lounici, H., & Figoli, A. (2019). Preparation and Characterization of TiO2-PVDF/PMMA Blend Membranes Using an Alternative Non-Toxic Solvent for UF/MF and Photocatalytic Application. Molecules, 24(4), 724. doi:10.3390/molecules24040724Marino, T., Russo, F., & Figoli, A. (2018). The Formation of Polyvinylidene Fluoride Membranes with Tailored Properties via Vapour/Non-Solvent Induced Phase Separation. Membranes, 8(3), 71. doi:10.3390/membranes8030071Liu, Z., Miao, Y.-E., Liu, M., Ding, Q., Tjiu, W. W., Cui, X., & Liu, T. (2014). Flexible polyaniline-coated TiO2/SiO2 nanofiber membranes with enhanced visible-light photocatalytic degradation performance. Journal of Colloid and Interface Science, 424, 49-55. doi:10.1016/j.jcis.2014.03.009Athanasekou, C. P., Morales-Torres, S., Likodimos, V., Romanos, G. E., Pastrana-Martinez, L. M., Falaras, P., … Silva, A. M. T. (2014). Prototype composite membranes of partially reduced graphene oxide/TiO2 for photocatalytic ultrafiltration water treatment under visible light. Applied Catalysis B: Environmental, 158-159, 361-372. doi:10.1016/j.apcatb.2014.04.012Rao, G., Zhang, Q., Zhao, H., Chen, J., & Li, Y. (2016). Novel titanium dioxide/iron (III) oxide/graphene oxide photocatalytic membrane for enhanced humic acid removal from water. Chemical Engineering Journal, 302, 633-640. doi:10.1016/j.cej.2016.05.095Chen, W., Ye, T., Xu, H., Chen, T., Geng, N., & Gao, X. (2017). An ultrafiltration membrane with enhanced photocatalytic performance from grafted N–TiO2/graphene oxide. RSC Advances, 7(16), 9880-9887. doi:10.1039/c6ra27666kShao, F., Xu, C., Ji, W., Dong, H., Sun, Q., Yu, L., & Dong, L. (2017). Layer-by-layer self-assembly TiO 2 and graphene oxide on polyamide reverse osmosis membranes with improved membrane durability. Desalination, 423, 21-29. doi:10.1016/j.desal.2017.09.007Chen, R., & Liu, H. (2011). Preparation of Cr-doped TiO2/SiO2 Photocatalysts and their Photocatalytic Properties. Journal of the Chinese Chemical Society, 58(7), 947-954. doi:10.1002/jccs.201190149Morris, R. E., Krikanova, E., & Shadman, F. (2004). Photocatalytic membrane for removal of organic contaminants during ultra-purification of water. Clean Technologies and Environmental Policy, 6(2), 96-104. doi:10.1007/s10098-003-0198-7Lopez, L. C., Buonomenna, M. G., Fontananova, E., Iacoviello, G., Drioli, E., d’ Agostino, R., & Favia, P. (2006). A New Generation of Catalytic Poly(vinylidene fluoride) Membranes: Coupling Plasma Treatment with Chemical Immobilization of Tungsten-Based Catalysts. Advanced Functional Materials, 16(11), 1417-1424. doi:10.1002/adfm.200500502Méricq, J.-P., Mendret, J., Brosillon, S., & Faur, C. (2015). High performance PVDF-TiO 2 membranes for water treatment. Chemical Engineering Science, 123, 283-291. doi:10.1016/j.ces.2014.10.047Safarpour, M., Vatanpour, V., & Khataee, A. (2016). Preparation and characterization of graphene oxide/TiO2 blended PES nanofiltration membrane with improved antifouling and separation performance. Desalination, 393, 65-78. doi:10.1016/j.desal.2015.07.003Mahlambi, M. M., Vilakati, G. D., & Mamba, B. B. (2014). Synthesis, Characterization, and Visible Light Degradation of Rhodamine B Dye by Carbon-Covered Alumina Supported Pd-TiO2/Polysulfone Membranes. Separation Science and Technology, 49(14), 2124-2134. doi:10.1080/01496395.2014.917105Kumar, M., Gholamvand, Z., Morrissey, A., Nolan, K., Ulbricht, M., & Lawler, J. (2016). Preparation and characterization of low fouling novel hybrid ultrafiltration membranes based on the blends of GO−TiO2 nanocomposite and polysulfone for humic acid removal. Journal of Membrane Science, 506, 38-49. doi:10.1016/j.memsci.2016.02.005Zhang, X., Lang, W.-Z., Yan, X., Lou, Z.-Y., & Chen, X.-F. (2016). Influences of the structure parameters of multi-walled carbon nanotubes(MWNTs) on PVDF/PFSA/O-MWNTs hollow fiber ultrafiltration membranes. Journal of Membrane Science, 499, 179-190. doi:10.1016/j.memsci.2015.10.034Castro-Muñoz, R., Galiano, F., de la Iglesia, Ó., Fíla, V., Téllez, C., Coronas, J., & Figoli, A. (2019). Graphene oxide – Filled polyimide membranes in pervaporative separation of azeotropic methanol–MTBE mixtures. Separation and Purification Technology, 224, 265-272. doi:10.1016/j.seppur.2019.05.034Grasso, G., Galiano, F., Yoo, M. J., Mancuso, R., Park, H. B., Gabriele, B., … Drioli, E. (2020). Development of graphene-PVDF composite membranes for membrane distillation. Journal of Membrane Science, 604, 118017. doi:10.1016/j.memsci.2020.118017Yao, Y., Miao, S., Yu, S., Ping Ma, L., Sun, H., & Wang, S. (2012). Fabrication of Fe3O4/SiO2 core/shell nanoparticles attached to graphene oxide and its use as an adsorbent. Journal of Colloid and Interface Science, 379(1), 20-26. doi:10.1016/j.jcis.2012.04.030Zhang, X., Cheng, C., Zhao, J., Ma, L., Sun, S., & Zhao, C. (2013). Polyethersulfone enwrapped graphene oxide porous particles for water treatment. Chemical Engineering Journal, 215-216, 72-81. doi:10.1016/j.cej.2012.11.009Marcano, D. C., Kosynkin, D. V., Berlin, J. M., Sinitskii, A., Sun, Z., Slesarev, A., … Tour, J. M. (2010). Improved Synthesis of Graphene Oxide. ACS Nano, 4(8), 4806-4814. doi:10.1021/nn1006368Geim, A. K., & Novoselov, K. S. (2007). The rise of graphene. Nature Materials, 6(3), 183-191. doi:10.1038/nmat1849Krishnamoorthy, K., Mohan, R., & Kim, S.-J. (2011). Graphene oxide as a photocatalytic material. Applied Physics Letters, 98(24), 244101. doi:10.1063/1.3599453Hou, W.-C., & Wang, Y.-S. (2017). Photocatalytic Generation of H2O2 by Graphene Oxide in Organic Electron Donor-Free Condition under Sunlight. ACS Sustainable Chemistry & Engineering, 5(4), 2994-3001. doi:10.1021/acssuschemeng.6b02635Stankovich, S., Dikin, D. A., Piner, R. D., Kohlhaas, K. A., Kleinhammes, A., Jia, Y., … Ruoff, R. S. (2007). Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide. Carbon, 45(7), 1558-1565. doi:10.1016/j.carbon.2007.02.034Li, S., Cui, Z., Zhang, L., He, B., & Li, J. (2016). The effect of sulfonated polysulfone on the compatibility and structure of polyethersulfone-based blend membranes. Journal of Membrane Science, 513, 1-11. doi:10.1016/j.memsci.2016.04.035Tseng, H.-H., Zhuang, G.-L., & Su, Y.-C. (2012). The effect of blending ratio on the compatibility, morphology, thermal behavior and pure water permeation of asymmetric CAP/PVDF membranes. Desalination, 284, 269-278. doi:10.1016/j.desal.2011.09.011Rehan, Z., Gzara, L., Khan, S., Alamry, K., El-Shahawi, M. S., Albeirutty, M., … Asiri, A. (2016). Synthesis and Characterization of Silver Nanoparticles-Filled Polyethersulfone Membranes for Antibacterial and Anti-Biofouling Application. Recent Patents on Nanotechnology, 10(3), 231-251. doi:10.2174/1872210510666160429145228Mousavi, S. M., & Zadhoush, A. (2017). Investigation of the relation between viscoelastic properties of polysulfone solutions, phase inversion process and membrane morphology: The effect of solvent power. Journal of Membrane Science, 532, 47-57. doi:10.1016/j.memsci.2017.03.006Wongchitphimon, S., Wang, R., Jiraratananon, R., Shi, L., & Loh, C. H. (2011). Effect of polyethylene glycol (PEG) as an additive on the fabrication of polyvinylidene fluoride-co-hexafluropropylene (PVDF-HFP) asymmetric microporous hollow fiber membranes. Journal of Membrane Science, 369(1-2), 329-338. doi:10.1016/j.memsci.2010.12.008Russo, F., Galiano, F., Pedace, F., Aricò, F., & Figoli, A. (2019). Dimethyl Isosorbide As a Green Solvent for Sustainable Ultrafiltration and Microfiltration Membrane Preparation. ACS Sustainable Chemistry & Engineering, 8(1), 659-668. doi:10.1021/acssuschemeng.9b06496Russo, F., Castro-Muñoz, R., Galiano, F., & Figoli, A. (2019). Unprecedented preparation of porous Matrimid® 5218 membranes. Journal of Membrane Science, 585, 166-174. doi:10.1016/j.memsci.2019.05.036Marino, T., Galiano, F., Simone, S., & Figoli, A. (2018). DMSO EVOL™ as novel non-toxic solvent for polyethersulfone membrane preparation. Environmental Science and Pollution Research, 26(15), 14774-14785. doi:10.1007/s11356-018-3575-9Bui, V.-T., Dao, V.-D., & Choi, H.-S. (2016). Transferable thin films with sponge-like porous structure via improved phase separation. Polymer, 101, 184-191. doi:10.1016/j.polymer.2016.08.063Meng, N., Priestley, R. C. E., Zhang, Y., Wang, H., & Zhang, X. (2016). The effect of reduction degree of GO nanosheets on microstructure and performance of PVDF/GO hybrid membranes. Journal of Membrane Science, 501, 169-178. doi:10.1016/j.memsci.2015.12.004Xie, Q., Xu, J., Feng, L., Jiang, L., Tang, W., Luo, X., & Han, C. C. (2004). Facile Creation of a Super-Amphiphobic Coating Surface with Bionic Microstructure. Advanced Materials, 16(4), 302-305. doi:10.1002/adma.200306281Razmjou, A., Arifin, E., Dong, G., Mansouri, J., & Chen, V. (2012). Superhydrophobic modification of TiO2 nanocomposite PVDF membranes for applications in membrane distillation. Journal of Membrane Science, 415-416, 850-863. doi:10.1016/j.memsci.2012.06.004Teow, Y. H., Ooi, B. S., & Ahmad, A. L. (2017). Fouling behaviours of PVDF-TiO2 mixed-matrix membrane applied to humic acid treatment. Journal of Water Process Engineering, 15, 89-98. doi:10.1016/j.jwpe.2016.03.005Wenzel, R. N. (1936). RESISTANCE OF SOLID SURFACES TO WETTING BY WATER. Industrial & Engineering Chemistry, 28(8), 988-994. doi:10.1021/ie50320a024Zhu, Z., Wang, L., Xu, Y., Li, Q., Jiang, J., & Wang, X. (2017). Preparation and characteristics of graphene oxide-blending PVDF nanohybrid membranes and their applications for hazardous dye adsorption and rejection. Journal of Colloid and Interface Science, 504, 429-439. doi:10.1016/j.jcis.2017.05.068Liu, Y., Jin, W., Zhao, Y., Zhang, G., & Zhang, W. (2017). Enhanced catalytic degradation of methylene blue by α-Fe2O3/graphene oxide via heterogeneous photo-Fenton reactions. Applied Catalysis B: Environmental, 206, 642-652. doi:10.1016/j.apcatb.2017.01.075Qin, J., Zhang, X., Yang, C., Cao, M., Ma, M., & Liu, R. (2017). ZnO microspheres-reduced graphene oxide nanocomposite for photocatalytic degradation of methylene blue dye. Applied Surface Science, 392, 196-203. doi:10.1016/j.apsusc.2016.09.043Oliveira, L. C. A., Gonçalves, M., Guerreiro, M. C., Ramalho, T. C., Fabris, J. D., Pereira, M. C., & Sapag, K. (2007). A new catalyst material based on niobia/iron oxide composite on the oxidation of organic contaminants in water via heterogeneous Fenton mechanisms. Applied Catalysis A: General, 316(1), 117-124. doi:10.1016/j.apcata.2006.09.027Houas, A. (2001). Photocatalytic degradation pathway of methylene blue in water. Applied Catalysis B: Environmental, 31(2), 145-157. doi:10.1016/s0926-3373(00)00276-9Kamble, S. P., Mangrulkar, P. A., Bansiwal, A. K., & Rayalu, S. S. (2008). Adsorption of phenol and o-chlorophenol on surface altered fly ash based molecular sieves. Chemical Engineering Journal, 138(1-3), 73-83. doi:10.1016/j.cej.2007.05.030Sirtori, C., Agüera, A., Gernjak, W., & Malato, S. (2010). Effect of water-matrix composition on Trimethoprim solar photodegradation kinetics and pathways. Water Research, 44(9), 2735-2744. doi:10.1016/j.watres.2010.02.006Yap, P.-S., & Lim, T.-T. (2011). Effect of aqueous matrix species on synergistic removal of bisphenol-A under solar irradiation using nitrogen-doped TiO2/AC composite. Applied Catalysis B: Environmental, 101(3-4), 709-717. doi:10.1016/j.apcatb.2010.11.013Stuart, M. A. C., Fleer, G. J., Lyklema, J., Norde, W., & Scheutjens, J. M. H. M. (1991). Adsorption of Ions, Polyelectrolytes and Proteins. Advances in Colloid and Interface Science, 34, 477-535. doi:10.1016/0001-8686(91)80056-

Graphene oxide as a catalyst for the diastereoselective transfer hydrogenation in the synthesis of prostaglandin derivatives

[EN] Modification of GO by organic molecules changes its catalytic activity in the hydrogen transfer from i-propanol to enones, affecting the selectivity to allyl alcohol and diastereoselectivity to the resulting stereoisomers. It is noteworthy the system does not contain metals and is recyclable.Coman, SM.; Podolean, I.; Tudorache, M.; Cojocaru, B.; Parvulescu, VI.; Puche Panadero, M.; García Gómez, H. (2017). Graphene oxide as a catalyst for the diastereoselective transfer hydrogenation in the synthesis of prostaglandin derivatives. Chemical Communications. 53(74):10271-10274. doi:10.1039/c7cc05105kS1027110274537

The oxidation of trichloroethylene over different mixed oxides derived from hydrotalcites

[EN] The activity of different Mg(Fe/Al), Ni(Fe/Al) and Co(Fe/Al) mixed oxides based on hydrotalcite-like compounds have been studied for the catalytic oxidation of trichloroethylene. It has been shown that the Co catalysts are more active than the Ni catalyst, being the Mg catalysts the less active ones. The activity of all the catalysts improves when iron is substituted by aluminum in the catalyst composition. The best results have been obtained with the CoAl mixed oxide derived from hydrotalcite that is a stable, highly active and selective catalyst. These results have been related with the presence of aluminum in the Co3O4 structure that favors, in the presence of oxygen, the formation of O2 − sites and enhances the acid properties of the catalyst. The combination of both characteristics maximizes the adsorption and oxidation of the TCE.The authors wish to thank financial support from CONACYT (project 154060) and from the Spanish Ministry of Economy and Competitiveness through the Consolider Ingenio Multicat (CSD-2009-00050) and MAT-2012-38567-C02-01 programms. N.B.R. acknowledges Catedra Cemex Sostenibilidad (UPV) for a fellowship.Blanch Raga, N.; Palomares Gimeno, AE.; Martínez Triguero, LJ.; Puche Panadero, M.; Fetter, G.; Bosch, P. (2014). The oxidation of trichloroethylene over different mixed oxides derived from hydrotalcites. Applied Catalysis B: Environmental. 160-61:129-134. https://doi.org/10.1016/j.apcatb.2014.05.014129134160-6