Suchergebnisse

The synthesis of chabazite with high solid yields is achieved by the rational combination of directing effects of a source of Si and Al coming from USY zeolites and the inexpensive tetraethylammonium. Moreover, Cu-CHA materials prepared by post-synthetic and "one-pot'' methodologies show high activity and stability for SCR of NOx. ; Financial support from the Spanish Government-MINECO through "Severo Ochoa'' (SEV 2012-0267), Consolider Ingenio 2010-Multicat, MAT2012-37160 and, Intramural-201480I015 is acknowledged. The authors thank Isabel Millet for technical support. ; Martin, N.; Moliner Marin, M.; Corma Canós, A. (2015). High yield synthesis of high-silica chabazite by combining the role of zeolite precursors and tetraethylammonium: SCR of NOx. Chemical Communications. 51(49):9965-9968. https://doi.org/10.1039/c5cc02670a ; S ; 9965 ; 9968 ; 51 ; 49

[EN] In the last few years, important efforts have been made to synthesize so-called "multipore" zeolites, which contain channels of different dimensions within the same crystalline structure. This is a very attractive subject, since the presence of pores of different sizes would favor the preferential diffusion of reactants and products through those different channel systems, allowing unique catalytic activities for specific chemical processes. In this Review we describe the most attractive achievements in the rational synthesis of multipore zeolites, containing small to extra-large pores, and the improvements reported for relevant chemical processes when these multipore zeolites have been used as catalysts. ; Financial support by the Spanish Government-MINECO through "Severo Ochoa" (SEV 2012-0267), Consolider Ingenio 2010-Multicat, MAT2012-37160, MAT2012-31657 and Intramural-201480I015 is acknowledged. ; Moliner Marin, M.; Martínez, C.; Corma Canós, A. (2015). Multipore zeolites: synthesis and catalytic applications. Angewandte Chemie International Edition. 54(12):3560-3579. https://doi.org/10.1002/anie.201406344 ; S ; 3560 ; 3579 ; 54 ; 12

[EN] The selective oxidation of propene to propene oxide (PO) is an industrially relevant and still challenging reaction that requires the design of highly specific catalysts able to improve simultaneously activity and selectivity. Metallic copper exhibits high selectivity toward propene epoxidation that drops when the catalyst surface is oxidized under reaction conditions. On the basis of previous work showing that small planar Cu-5 clusters are more resistant to oxidation than 3D ones, we have performed a detailed theoretical study of the mechanism of propene oxidation with molecular O-2 and atomic O adsorbed on both planar and 3D Cu-5 clusters. The desired pathways leading to PO as well as the undesired routes producing propanal, acetone, or allyl intermediates that finally evolve to acrolein or CO2 have been considered, and the global analysis of all data indicates that planar Cu-5 clusters are promising candidates for the selective epoxidation of propene ; This work has been supported by the European Union through ERC-AdG-2014-671093 (SynCatMatch) and by the Spanish Government through "Severo Ochoa"(SEV-2016-0683, MINECO) and MAT2017-82288-C2-1-P (AEI/FEDER, UE) Projects. E.F.V. thanks Spanish MINECO for her fellowship SVP-2013-068146. ; Fernández Villanueva, E.; Boronat Zaragoza, M.; Corma Canós, A. (2020). The Crucial Role of Cluster Morphology on the Epoxidation of Propene Catalyzed by Cu-5: A DFT Study. The Journal of Physical Chemistry C. 124(39):21549-21558. https://doi.org/10.1021/acs.jpcc.0c06295 ; S ; 21549 ; 21558 ; 124 ; 39

[EN] In this work, a catalytic method is presented for the synthesis of aromatic carbamates from aromatic amines using dimethyl carbonate instead of phosgene as a green and safe reaction process. Microcrystalline Zr-MOF-808 is reported as an active and efficient heterogeneous catalyst for the selective carbamoylation of anilines and industrially relevant aromatic diamines, under mild reaction conditions with near quantitative yields. We have accomplished the selective growth of well-dispersed Zr-MOF-808 nanocrystals within the mesoporous material MCM-41. A superior catalytic performance of the Zr-MOF808@MCM-41 is demonstrated that together with increased stability stands out as an advantageous heterogeneous catalyst for polyurethane production. In situ FTIR studies have allowed a better understanding of the reaction pathway at the molecular level when the active MOF catalyst is present. ; This work was funded by the European Union through the European Research Council (grant ERC-AdG-2014-671093, SynCatMatch) and by the Spanish government through the Severo Ochoa program (SEV-2016-0683). S.R.-B. acknowledges a PhD fellowship from the Generalitat Valenciana. The Electron Microscopy Service of the Universitat Politecnica de Valenciais acknowledged for their help in sample characterization. ; Rojas-Buzo, S.; García-García, P.; Corma Canós, A. (2019). Zr-MOF-808@MCM-41 catalyzed phosgene-free synthesis of polyurethane precursors. Catalysis Science & Technology. 9(1):146-156. https://doi.org/10.1039/c8cy02235f ; S ; 146 ; 156 ; 9 ; 1 ; Tundo, P., & Selva, M. (2002). The Chemistry of Dimethyl Carbonate. Accounts of Chemical Research, 35(9), 706-716. doi:10.1021/ar010076f ; Fiorani, G., Perosa, A., & Selva, M. (2018). Dimethyl carbonate: a versatile reagent for a sustainable valorization of renewables. Green Chemistry, 20(2), 288-322. doi:10.1039/c7gc02118f ; Tundo, P., Rossi, L., & Loris, A. (2005). Dimethyl Carbonate as an Ambident Electrophile. The Journal of Organic Chemistry, 70(6), 2219-2224. ...

[EN] The influence of the crystallographic phase of ZrO2 on its catalytic performance in the MPV reduction of cyclohexanone with propan-2-ol has been systematically investigated by combining accurate synthesis procedures, XRD and HRTEM characterization, kinetic measurements and DFT calculations, and compared to that of Zr-beta zeolite. The higher intrinsic activity of monoclinic zirconia as compared to other ZrO2 phases is not due to a lower activation energy for the rate-determining step, but to an adequate distribution of reactant fragments on the catalyst surface, indicating a structure-activity relationship for this reaction when catalyzed by ZrO2 and also by Zr-beta zeolite. Inexpensive and stable ZrO2 catalysts for the MPV reaction have been obtained by controlling the crystallographic phase of the synthesized material. ; This work has been supported by the Spanish Government through the "Severo Ochoa Program" (SEV 2012-0267). The Electron Microscopy Service of the UPV is acknowledged for their help in sample characterization. The Red Espanola de Supercomputacion (RES) and Centre de Calcul de la Universitat de Valencia are gratefully acknowledged for computational facilities and technical assistance. F. Gonell is grateful to Ministerio de Educacion, Cultura y Deporte for a PhD grant (AP2010-2748). ; Gonell-Gómez, F.; Boronat Zaragoza, M.; Corma Canós, A. (2017). Structure-reactivity relationship in isolated Zr sites present in Zr-zeolite and ZrO2 for the Meerwein-Ponndorf-Verley reaction. Catalysis Science & Technology. 7(13):2865-2873. https://doi.org/10.1039/c7cy00567a ; S ; 2865 ; 2873 ; 7 ; 13

The combination of Cu(II) triethylenetetramine and N,N-dimethyl-3,5-dimethylpiperidinium as structure directing agents allowed the direct preparation of highly active and hydrothermally stable Cu-SAPO-18 for the selective catalytic reduction of NOx with NH3. The approach allows performing a one-pot synthesis avoiding intermediate calcination and ion exchange, while achieving complete framework Si isolation. Combination of physicochemical characterization techniques show that copper exists as extra-framework Cu2+, which have been identified as the specific active sites for the SCR of NOx. The selective presence of isolated Si species in the zeolitic framework introduces high hydrothermal stability. ; Financial support by the Spanish Government-MINECO through "Severo Ochoa" (SEV 2012-0267), Consolider Ingenio 2010-Multicat, MAT2012-37160 and, Intramural-2014801015 is acknowledged. The authors thank Isabel Millet for technical support. ; Martínez Franco, R.; Moliner Marin, M.; Corma Canós, A. (2014). Direct synthesis design of Cu-SAPO-18, a very efficient catalyst for the SCR of NOx. Journal of Catalysis. 319:36-43. https://doi.org/10.1016/j.jcat.2014.08.005 ; S ; 36 ; 43 ; 319

[EN] In this work, we will report the generation of Au clusters in a purely siliceous MCM-22 zeolite. The catalytic properties of these Au clusters have been tested for the selective oxidation of cyclohexane to cyclohexanol and cyclohexanone (KA-oil). The Au clusters encapsulated in the MCM-22 zeolite are highly active and selective for the oxidation of cyclohexane to KA-oil, which is superior to Au nanoparticles on the same support. These results suggest that Au clusters are highly active for the activation of oxygen to produce radical species. ; This work has been supported by the European Union through the European Research Council (grant ERC-AdG-2014-671093, SynCatMatch) and the Spanish government through the "Severo Ochoa Program" (SEV-2016-0683). The authors also thank the Microscopy Service of UPV for kind help with TEM and STEM measurements. Mr J. A. Gaona is greatly acknowledged for his very helpful assistance on the catalytic studies. The XAS data were acquired at European Synchrotron Radiation Facility. The HAADF-HRSTEM studies were conducted in the Laboratorio de Microscopias Avanzadas (LMA) at the Instituto de Nanociencia de Aragon (INA)-Universidad de Zaragoza (Spain), Spanish ICTS National facility. R. A. gratefully acknowledges the support from the Spanish Ministry of Economy and Competitiveness (MINECO) through project grant MAT2016-79776-P (AEI/FEDER, UE). ; Liu, L.; Arenal, R.; Meira, DM.; Corma Canós, A. (2019). Generation of gold nanoclusters encapsulated in an MCM-22 zeolite for the aerobic oxidation of cyclohexane. Chemical Communications. 55(11):1607-1610. https://doi.org/10.1039/c8cc07185c ; S ; 1607 ; 1610 ; 55 ; 11 ; Claus, P. (2005). Heterogeneously catalysed hydrogenation using gold catalysts. Applied Catalysis A: General, 291(1-2), 222-229. doi:10.1016/j.apcata.2004.12.048 ; Hashmi, A. S. K., & Hutchings, G. J. (2006). Gold Catalysis. Angewandte Chemie International Edition, 45(47), 7896-7936. doi:10.1002/anie.200602454 ; Liu, L., & Corma, A. (2018). Metal Catalysts for ...

1607 1610 55 11 ; S ; [EN] In this work, we will report the generation of Au clusters in a purely siliceous MCM-22 zeolite. The catalytic properties of these Au clusters have been tested for the selective oxidation of cyclohexane to cyclohexanol and cyclohexanone (KA-oil). The Au clusters encapsulated in the MCM-22 zeolite are highly active and selective for the oxidation of cyclohexane to KA-oil, which is superior to Au nanoparticles on the same support. These results suggest that Au clusters are highly active for the activation of oxygen to produce radical species. This work has been supported by the European Union through the European Research Council (grant ERC-AdG-2014-671093, SynCatMatch) and the Spanish government through the "Severo Ochoa Program" (SEV-2016-0683). The authors also thank the Microscopy Service of UPV for kind help with TEM and STEM measurements. Mr J. A. Gaona is greatly acknowledged for his very helpful assistance on the catalytic studies. The XAS data were acquired at European Synchrotron Radiation Facility. The HAADF-HRSTEM studies were conducted in the Laboratorio de Microscopias Avanzadas (LMA) at the Instituto de Nanociencia de Aragon (INA)-Universidad de Zaragoza (Spain), Spanish ICTS National facility. R. A. gratefully acknowledges the support from the Spanish Ministry of Economy and Competitiveness (MINECO) through project grant MAT2016-79776-P (AEI/FEDER, UE). Liu, L.; Arenal, R.; Meira, DM.; Corma Canós, A. (2019). Generation of gold nanoclusters encapsulated in an MCM-22 zeolite for the aerobic oxidation of cyclohexane. Chemical Communications. 55(11):1607-1610. https://doi.org/10.1039/c8cc07185c Claus, P. (2005). Heterogeneously catalysed hydrogenation using gold catalysts. Applied Catalysis A: General, 291(1-2), 222-229. doi:10.1016/j.apcata.2004.12.048 Hashmi, A. S. K., & Hutchings, G. J. (2006). Gold Catalysis. Angewandte Chemie International Edition, 45(47), 7896-7936. doi:10.1002/anie.200602454 Liu, L., & Corma, A. (2018). Metal Catalysts for Heterogeneous ...

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Catalysis, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/acscatal.7b04260 ; [EN] Herein, a general protocol for the preparation of a broad range of valuable N-heterocyclic products by hydrogenation of quinolines and related N-heteroarenes is described. Interestingly, the catalytic hydrogenation of the N-heteroarene ring is chemoselectively performed when other facile reducible functional groups, including alkenes, ketones, cyanides, carboxylic acids, esters, and amides, are present. The key to successful catalysis relies on the use of a nanolayered cobalt-molybdenum sulfide catalyst hydrothermally synthesized from earth-abundant metal precursors. This heterogeneous system displays a tunable composition of phases that allows for catalyst regeneration. Its catalytic activity depends on the composition of the mixed phase of cobalt sulfides, being higher with the presence of Co3S4, and could also be associated with the presence of transient Co-Mo-S structures that mainly vanish after the first catalytic run. ; Financial support by the Spanish Government-MINECO through the program "Severo Ochoa" (SEV-2016-0683) is gratefully acknowledged. I.S. also thanks the Spanish Government-MINECO for a "Formacion Postdoctoral" fellowship and Vice-Rectorate for Research, Innovation and Transfer of the Universitat Politecnica de Valencia (UPV) for a postdoctoral fellowship. The authors also thank the Microscopy Service of UPV for kind help with TEM and STEM measurements. ; Sorribes, I.; Liu, L.; Doménech Carbó, A.; Corma Canós, A. (2018). Nanolayered Cobalt-Molybdenum Sulfides as Highly Chemo- and Regioselective Catalysts for the Hydrogenation of Quinoline Derivatives. ACS Catalysis. 8(5):4545-4557. https://doi.org/10.1021/acscatal.7b04260 ; S ; 4545 ; 4557 ; 8 ; 5

4545 4557 8 5 ; S ; This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Catalysis, © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/acscatal.7b04260 [EN] Herein, a general protocol for the preparation of a broad range of valuable N-heterocyclic products by hydrogenation of quinolines and related N-heteroarenes is described. Interestingly, the catalytic hydrogenation of the N-heteroarene ring is chemoselectively performed when other facile reducible functional groups, including alkenes, ketones, cyanides, carboxylic acids, esters, and amides, are present. The key to successful catalysis relies on the use of a nanolayered cobalt-molybdenum sulfide catalyst hydrothermally synthesized from earth-abundant metal precursors. This heterogeneous system displays a tunable composition of phases that allows for catalyst regeneration. Its catalytic activity depends on the composition of the mixed phase of cobalt sulfides, being higher with the presence of Co3S4, and could also be associated with the presence of transient Co-Mo-S structures that mainly vanish after the first catalytic run. Financial support by the Spanish Government-MINECO through the program "Severo Ochoa" (SEV-2016-0683) is gratefully acknowledged. I.S. also thanks the Spanish Government-MINECO for a "Formacion Postdoctoral" fellowship and Vice-Rectorate for Research, Innovation and Transfer of the Universitat Politecnica de Valencia (UPV) for a postdoctoral fellowship. The authors also thank the Microscopy Service of UPV for kind help with TEM and STEM measurements. Sorribes, I.; Liu, L.; Doménech Carbó, A.; Corma Canós, A. (2018). Nanolayered Cobalt-Molybdenum Sulfides as Highly Chemo- and Regioselective Catalysts for the Hydrogenation of Quinoline Derivatives. ACS Catalysis. 8(5):4545-4557. https://doi.org/10.1021/acscatal.7b04260

[EN] Novel bifunctional acid base monolayered hybrid catalysts (MLHMs), based on associated individual (organo)aluminosilicate sheets with amino and sulfonic pending groups located in the interlayer space, have been successfully prepared by direct alkaline hydrothermal synthesis and evaluated in consecutive catalytic transformations. Different characterization techniques such as chemical and thermogravimetrical analyses, X-ray diffraction, TEM microscopy, nuclear magnetic resonance (NMR), temperature programmed desorption of CO2 and NH3 (TPD), and textural measurements were used to show the physicochemical and structural nature of the materials, evidencing their effectiveness as functional acid, base, and acid base catalysts for different one pot two-step tandem reactions, which were performed in the presence of only one active and recoverable lamellar-type hybrid solid catalyst. ; The authors are grateful for financial support from the Spanish Government by MAT2014-52085-C2-1-P and Severo Ochoa Excellence Program SEV-2012-0267. A.G. thanks predoctoral fellowships from MINECO for economical support (reference number BES-2012-052429). The European Union is also acknowledged by ERC-AdG-2014-671093-SynCatMatch. ; Gaona Cordero, A.; Díaz Morales, UM.; Corma Canós, A. (2017). Functional Acid and Base Hybrid Catalysts Organized by Associated (Organo)aluminosilicate Layers for C-C Bond Forming Reactions and Tandem Processes. Chemistry of Materials. 29(4):1599-1612. https://doi.org/10.1021/acs.chemmater.6b04563 ; S ; 1599 ; 1612 ; 29 ; 4

[EN] The interaction of small molecules with acid-base and redox centers in small Ce21O42 nanoparticles has been theoretically investigated using the DFT + U approach with the PW91 functional and U = 0.2 and 4 eV, in order to determine the influence of the U value on the trends observed in selected properties describing such interactions. CO adsorption at low coordinated Ce4+ Lewis acid centers, water adsorption and dissociation at acid-base pairs, formation of oxygen vacancy defects by removal of an oxygen atom from the system, and interaction of molecular O-2 with such defects have been considered. The largest effect of the value of U is found for the description of the reduced Ce21O41 nanoparticle. In all other cases involving stoichiometric and oxidized Ce21O42 and Ce21O43 systems, the trends in the calculated adsorption and reaction energies, optimized geometries, charge distribution, and vibrational frequencies are quite similar at the three levels considered. ; Financial support from the Spanish Science and Innovation Ministry (Consolider Ingenio 2010-MULTICAT CSD2009-00050 and Subprograma de apoyo a Centros y Universidades de Excelencia Severo Ochoa SEV 2012 0267) is acknowledged. The European Union is also acknowledged by ERC-AdG-2014-671093 — SynCatMatch. Red Española de Supercomputación (RES) and Centre de Càlcul de la Universitat de València are gratefully acknowledged for computational facilities and technical assistance. T. L.-A. thanks ITQ for a contract. We thank Konstantin Neyman for providing the Ce21O42 nanoparticle model. ; Boronat Zaragoza, M.; López Auséns, JT.; Corma Canós, A. (2016). The acid-base and redox reactivity of CeO2 nanoparticles: Influence of the Hubbard U term in DFT plus U studies. Surface Science. 648:212-219. https://doi.org/10.1016/j.susc.2015.10.047 ; S ; 212 ; 219 ; 648

212 219 648 ; S ; [EN] The interaction of small molecules with acid-base and redox centers in small Ce21O42 nanoparticles has been theoretically investigated using the DFT + U approach with the PW91 functional and U = 0.2 and 4 eV, in order to determine the influence of the U value on the trends observed in selected properties describing such interactions. CO adsorption at low coordinated Ce4+ Lewis acid centers, water adsorption and dissociation at acid-base pairs, formation of oxygen vacancy defects by removal of an oxygen atom from the system, and interaction of molecular O-2 with such defects have been considered. The largest effect of the value of U is found for the description of the reduced Ce21O41 nanoparticle. In all other cases involving stoichiometric and oxidized Ce21O42 and Ce21O43 systems, the trends in the calculated adsorption and reaction energies, optimized geometries, charge distribution, and vibrational frequencies are quite similar at the three levels considered. Financial support from the Spanish Science and Innovation Ministry (Consolider Ingenio 2010-MULTICAT CSD2009-00050 and Subprograma de apoyo a Centros y Universidades de Excelencia Severo Ochoa SEV 2012 0267) is acknowledged. The European Union is also acknowledged by ERC-AdG-2014-671093 — SynCatMatch. Red Española de Supercomputación (RES) and Centre de Càlcul de la Universitat de València are gratefully acknowledged for computational facilities and technical assistance. T. L.-A. thanks ITQ for a contract. We thank Konstantin Neyman for providing the Ce21O42 nanoparticle model. Boronat Zaragoza, M.; López Auséns, JT.; Corma Canós, A. (2016). The acid-base and redox reactivity of CeO2 nanoparticles: Influence of the Hubbard U term in DFT plus U studies. Surface Science. 648:212-219. https://doi.org/10.1016/j.susc.2015.10.047

[EN] The hydrothermal carbonization (HTC) is a very suitable process to transform wet biomass feedstocks into a peat-like material without drying the biomass input. Therefore, the energetic balance is more favorable than for alternative processes converting biomass as a whole. Further synergies can be achieved when the plant is employed as central hub for a regional biorefinery. Hence, a HTC pilot plant is operated with garden prunings and monitored during two years. It is shown that the elemental composition of HTC carbon is relatively constant. A carbon content of higher than 60% (based on dry, ash-free matter) is achieved. Fixed carbon content and volatile matter show low variation being the volatile content quite high with 61% on average. Dried in a post-process treatment which is less energy-demanding than drying of the raw biomass and pressed into pellets or briquettes the HTC carbon can be used as solid biofuel fulfilling the European standard (EN 14961-6). With a regional thermal valorization of the biofuel the ashes can be returned as phosphorous source to the crop land from which the biomass was harvested. Part of the process water, which involves a high amount of potassium, can be used for crop irrigation. In this way, valuable plant nutrients are recovered for soil remediation. Hence, closing the nutrient cycles a HTC plant can be considered as a sustainable local biorefinery producing a solid biofuel. Thereby, solar energy is exploited which was fixed before by photosynthesis together with the carbon dioxide which is liberated in the combustion of the solid biofuel. Optionally, the process water might serve as an alternative source of energy as it is demonstrated that its carbon content can be exploited for biogas production ; Authors are grateful for financial support obtained from the Spanish Ministry of Economy and Competitiveness (Innpacto Programme, IPT-2012-0023-120000) and the European Union (FP7-SME-2013-605178-NEW APP). ; Hitzl, M.; Corma Canós, A.; Pomares Garcia, F.; Renz, M. (2015). The ...

[EN] In this work some relevant processes for the preparation of liquid hydrocarbon fuels and fuel additives from cellulose, hemicellulose and triglycerides derived platform molecules are discussed. Thus, it is shown that a series of platform molecules such as levulinic acid, furans, fatty acids and polyols can be converted into a variety of fuel additives through catalytic transformations that include reduction, esterification, etherification, and acetalization reactions. Moreover, we will show that liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenolysis, hydrogenation, decarbonylation/descarboxylation etc.) with the adjustment of the molecular weight via C C coupling reactions (e.g. aldol condensation, hydroxyalkylation, oligomerization, ketonization) of the reactive platform molecules. ; This work has been supported by the Spanish Government-MINECO through Consolider Ingenio 2010-Multicat and CTQ.-2011-27550, ITQ thanks the "Program Severo Ochoa" for financial support. ; Climent Olmedo, MJ.; Corma Canós, A.; Iborra Chornet, S. (2014). Conversion of biomass platform molecules into fuel additives and liquid hydrocarbon fuels. Green Chemistry. 16(2):516-547. https://doi.org/10.1039/c3gc41492b ; S ; 516 ; 547 ; 16 ; 2