55 research outputs found
Synthesis design and structure of a multipore zeolite with interconnected 12- and 10-MR channels
[EN] A new molecular sieve, ITQ-38, containing interconnected large and medium pores in its structure has been synthesized. The rational combination of dicationic piperidine-derivative molecules as organic structure directing agents (OSDAs) with germanium and boron atoms in alkaline media has allowed the synthesis of ITQ-38 zeolite. High-resolution transmission electron microscopy (HRTEM) has been used to elucidate the framework topology of ITQ-38, revealing the presence of domains of perfect ITQ-38 crystals as well as very small areas containing nanosized ITQ-38/ITQ-22 intergrowths. The structure of ITQ-38 is highly related to ITQ-22 and the recently described polymorph C of ITQ-39 zeolite. It shares a common building layer with ITQ-22 and contains the same building unit as the polymorph C of ITQ-39. All three structures present similar framework density, 16.1 T atoms/1000 angstrom(3).Financial support by the Spanish MICINN (MAT2009-14528-C02-01 and MAT2006-14274-C02-01), Consolider Ingenio 2010-Multicat, Generalitat Valenciana by the PROMETEO program, UPV through PAJD-06-11 (n.1952), the Swedish Research Council (VR), the Swedish Governmental Agency for Innovation Systems (VINNOVA) and Goran Gustafsson Foundtion for Natural Sciences and Medical Research, is acknowledged. Manuel Moliner also acknowledges the "Subprograma Ramon y Cajal" for the contract RYC-2011-08972. Wei Wan was supported by a postdoctoral grant from the Carl-Trygger Foundation. The EM facility was supported by Knut and Alice Wallenberg Foundation. The authors thank the beamline BM01B at ESRF in Grenoble for beamtime allocation (exp. CH-2493). Gunnel Karlsson is kindly thanked for TEM sample preparation by ultramicrotomy. Dedicated to Prof. Miguel A. Miranda on his 60th Birthday.Moliner Marin, M.; Willhammar, T.; Wan, W.; González, J.; Rey Garcia, F.; Jorda Moret, JL.; Zou, X.... (2012). Synthesis design and structure of a multipore zeolite with interconnected 12- and 10-MR channels. Journal of the American Chemical Society. 134(14):6473-6478. https://doi.org/10.1021/ja301082nS647364781341
Coloration and Fire Retardancy of Transparent Wood Composites by Metal Ions
Transparent wood composites (TWs) offer the possibility of unique coloration effects. A colored transparent wood composite (C-TW) with enhanced fire retardancy was impregnated by metal ion solutions, followed by methyl methacrylate (MMA) impregnation and polymerization. Bleached birch wood with a preserved hierarchical structure acted as a host for metal ions. Cobalt, nickel, copper, and iron metal salts were used. The location and distribution of metal ions in C-TW as well as the mechanical performance, optical properties, and fire retardancy were investigated. The C-TW coloration is tunable by controlling the metal ion species and concentration. The metal ions reduced heat release rates and limited the production of smoke during forced combustion tests. The potential for scaled-up production was verified by fabricating samples with a dimension of 180 x 100 x 1 (l x b x h) mm(3)
Tunable CHA/AEI Zeolite Intergrowths with A Priori Biselective Organic Structure-Directing Agents: Controlling Enrichment and Implications for Selective Catalytic Reduction of NOx
[EN] A novel ab initio methodology based on high-throughput simulations has permitted designing unique biselective organic structure-directing agents (OSDAs) that allow the efficient synthesis of CHA/AEI zeolite intergrowth materials with controlled phase compositions. Distinctive local crystallographic ordering of the CHA/AEI intergrowths was revealed at the nanoscale level using integrated differential phase contrast scanning transmission electron microscopy (iDPC STEM). These novel CHA/AEI materials have been tested for the selective catalytic reduction (SCR) of NOx, presenting an outstanding catalytic performance and hydrothermal stability, even surpassing the performance of the well-established commercial CHA-type catalyst. This methodology opens the possibility for synthetizing new zeolite intergrowths with more complex structures and unique catalytic properties.E.B.-J., C.P., M.M. and A.C. acknowledge financial support by the Spanish Government [Grant RTI2018-101033-B-I00 (MCIU/AEI/FEDER, UE)], and by CSIC [I-link+ Program (LINKA20381)]. D.S.-K. and R.G.-B. acknowledge the Energy Initiative (MITEI) and MIT International Science and Technology Initiatives (MISTI) Seed Funds. D.S.-K. was additionally funded by the MIT Energy Fellowship. Y.R.-L acknowledges support by the U.S. Department of Energy, Office of Basic Energy Sciences under Award DE-SC0016214. E.B.-J. acknowledges the Spanish Government for an FPI scholarship (PRE2019-088360). T.W. acknowledges financial support by the Swedish Research Council (Grant No. 2019-05465). T.W. and T.U. acknowledge funding from the Swedish Strategic Res. Foundation (project nr. ITM17-0301). The Electron Microscopy Service of the UPV is also acknowledged for their help in sample characterization. Computer calculations were executed at the Massachusetts Green High-Performance Computing Center with support from MIT Research Computing, and at the Extreme Sci. and Eng. Discovery Environment (XSEDE)[33] Expanse through allocation TG-DMR200068.Bello-Jurado, E.; Schwalbe-Koda, D.; Nero, M.; Paris, C.; Uusimäki, T.; Román-Leshkov, Y.; Corma Canós, A.... (2022). Tunable CHA/AEI Zeolite Intergrowths with A Priori Biselective Organic Structure-Directing Agents: Controlling Enrichment and Implications for Selective Catalytic Reduction of NOx. Angewandte Chemie International Edition. 61(28):1-6. https://doi.org/10.1002/anie.20220183716612
A Novel Porous Ti-Squarate as Efficient Photocatalyst in the Overall Water Splitting Reaction under Simulated Sunlight Irradiation
A new porous titanium(IV) squarate metal–organic framework (MOF), denoted as IEF-11, having a never reported titanium secondary building unit, is successfully synthesized and fully characterized. IEF-11 not only exhibits a permanent porosity but also an outstanding chemical stability. Further, as a consequence of combining the photoactive Ti(IV) and the electroactive squarate, IEF-11 presents relevant optoelectronic properties, applied here to the photocatalytic overall water splitting reaction. Remarkably, IEF-11 as a photocatalyst is able to produce record H amounts for MOF-based materials under simulated sunlight (up to 672 µmol g in 22 h) without any activity loss during at least 10 d.P.S.-A. and A.A.B. contributed equally to this work. The authors acknowledge the Ramón Areces Foundation project H+MOFs, the M-ERA-NET C-MOF-cell (grant PCI2020-111998 funded by MCIN/AEI /10.13039/501100011033 and European Union NextGenerationEU/PRTR) project, and Retos Investigación MOFSEIDON (grant PID2019-104228RB-I00 funded by MCIN/AEI/10.13039/501100011033) project. S.N. thanks financial support by Ministerio de Ciencia, Innovatión y Universidades RTI2018-099482-A-I00 project and Agència Valenciana de la Innovació (AVI, INNEST/2020/111) project. H.G. thanks financial support to the Spanish Ministry of Science and Innovation (Severo Ochoa and RTI2018-098237-CO21) and Generalitat Valenciana (Prometeo2017/083). T.W. acknowledges financial support from the Swedish Research Council (VR, 2019-05465). Parts of this research were carried out at “CRISTAL” at SOLEIL. P.S. and A.A.B. sincerely thank to the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020 for the support of the synchrotron experiment
NH3-SCR catalysts for heavy-duty diesel vehicles: Preparation of CHA-type zeolites with low-cost templates
Computer-assistance allows selecting the most adequate low-cost organic structure directing agents (OSDAs) for the crystallization of Al-rich CHA-type zeolites. The host-guest stabilization energies of tetraethylammonium (TEA), methyltriethylammonium (MTEA) and dimethyldiethylammonium (DMDEA), in combination with Na, were first theoretically evaluated. This “ab-initio” analysis reveals that two TEA show a serious steric hindrance in a cha cavity, whereas two MTEA would present excellent host-guest confinements. The synthesis of Al-rich CHA-type zeolites has been accomplished using TEA and MTEA. Electron diffraction and high-resolution transmission electron microscopy reveal large CHA-domains with narrow faulted GME-domains in the CHA-type material synthesized with TEA, confirming the better OSDA-directing roles of MTEA cations towards the cha cavity, in good agreement with DFT calculations. Cu-exchanged Al-rich CHA-type samples achieved with MTEA and TEA show excellent catalytic activity and hydrothermal stability for the selective catalytic reduction (SCR) of NOx with ammonia under conditions relevant for future heavy duty diesel conditions.This work has been supported by Umicore and by the Spanish Government-MCIU through RTI2018-101033-B-I00 (MCIU/AEI/FEDER, UE) and PID2020-112590GB-C21 (AEI/FEDER, UE). T.W. acknowledges financial support by the Swedish Research Council (Grant No. 2019-05465). E.B. acknowledges the Spanish Government-MCIU for a FPI scholarship (PRE2019-088360). P.F. thanks ITQ for a contract. The Electron Microscopy Service of the UPV is acknowledged for their help in sample characterization. The computations were performed on the Tirant III cluster of the Servei d'Informàtica of the University of Valencia
A Novel Porous Ti-Squarate as Efficient Photocatalyst in the Overall Water Splitting Reaction under Simulated Sunlight Irradiation
[EN] A new porous titanium(IV) squarate metal¿organic framework (MOF),
denoted as IEF-11, having a never reported titanium secondary building unit,
is successfully synthesized and fully characterized. IEF-11 not only exhibits
a permanent porosity but also an outstanding chemical stability. Further,
as a consequence of combining the photoactive Ti(IV) and the electroactive
squarate, IEF-11 presents relevant optoelectronic properties, applied here to
the photocatalytic overall water splitting reaction. Remarkably, IEF-11 as a
photocatalyst is able to produce record H2 amounts for MOF-based materials
under simulated sunlight (up to 672 µmol gcatalyst in 22 h) without any activity
loss during at least 10 d.P.S.-A. and A.A.B. contributed equally to this work. The authors acknowledge the Ramón Areces Foundation project H+MOFs, the M-ERA-NET C-MOF-cell (grant PCI2020-111998 funded by MCIN/AEI/10.13039/501100011033 and European Union NextGenerationEU/ PRTR) project, and Retos Investigación MOFSEIDON (grant PID2019-104228RB-I00 funded by MCIN/AEI/10.13039/501100011033) project.
S.N. thanks financial support by Ministerio de Ciencia, Innovatión y Universidades RTI2018-099482-A-I00 project and Agència Valenciana de la Innovació (AVI, INNEST/2020/111) project. H.G. thanks financial support to the Spanish Ministry of Science and Innovation (Severo Ochoa and RTI2018-098237-CO21) and Generalitat Valenciana (Prometeo2017/083). T.W. acknowledges financial support from the Swedish Research Council (VR, 2019-05465). Parts of this research were carried out at ¿CRISTAL¿ at SOLEIL. P.S. and A.A.B. sincerely thank to
the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020 for the support of the synchrotron experiment.Salcedo-Abraira, P.; Babaryk, AA.; Montero-Lanzuela, E.; Contreras Almengor, OR.; Cabrero-Antonino, M.; Svensson, E.; Willhammar, T.... (2021). A Novel Porous Ti-Squarate as Efficient Photocatalyst in the Overall Water Splitting Reaction under Simulated Sunlight Irradiation. Advanced Materials. 33(52):1-9. https://doi.org/10.1002/adma.20210662719335
A priori control of zeolite phase competition and intergrowth with high-throughput simulations
Zeolites are versatile catalysts and molecular sieves with large topological diversity, but managing phase competition in zeolite synthesis is an empirical, labor-intensive task. In this work, we controlled phase selectivity in templated zeolite synthesis from first principles by combining high-throughput atomistic simulations, literature mining, human-computer interaction, synthesis, and characterization. Proposed binding metrics distilled from more than 586,000 zeolite-molecule simulations reproduced the extracted literature and rationalized framework competition in the design of organic structure-directing agents. Energetic, geometric, and electrostatic descriptors of template molecules were found to regulate synthetic accessibility windows and aluminum distributions in pure-phase zeolites. Furthermore, these parameters allowed us to realize an intergrowth zeolite through a single bi-selective template. The computation-first approach enables control of both zeolite synthesis and structure composition using a priori theoretical descriptors.D.S.-K. and R.G.-B. acknowledge the Energy Initiative (MITEI) and MIT International Science and Technology Initiatives (MISTI) Seed Funds. D.S.-K. was also funded by the MIT Energy Fellowship. C.P., E.B.-J., M.M., and A.C. acknowledge financial support by the Spanish government through the “Severo Ochoa” program (SEV-2016-0683, MINECO) and grant RTI2018-101033-B-I00 (MCIU/AEI/FEDER, UE). E.B.-J. acknowledges the Spanish government for an FPI scholarship (PRE2019-088360). Z.J., E.O., S.K., and Y.R.-L. acknowledge partial funding from Designing Materials to Revolutionize and Engineer our Future (DMREF) from the National Science Foundation (NSF); awards 1922311, 1922372, and 1922090; and the Office of Naval Research (ONR) under contract N00014-20-1-2280. S.K. was additionally funded by the Kwanjeong Educational Fellowship. Z.J. was also supported by the Department of Defense (DoD) through the National Defense Science Engineering Graduate (NDSEG) fellowship program. T.W. acknowledges financial support by the Swedish Research Council (grant no. 2019-05465). Computer calculations were executed at the Massachusetts Green High-Performance Computing Center with support from MIT Research Computing and at the Extreme Science and Engineering Discovery Environment (XSEDE) (53) Expanse through allocation TG-DMR200068
A Robust and Biocompatible Bismuth Ellagate MOF Synthesized Under Green Ambient Conditions
The first bioinspired microporous metal-organic framework (MOF) synthesized using ellagic acid, a common natural antioxidant and polyphenol building unit, is presented. Bi2O(H2O)2(C14H2O8)\ub7nH2O (SU-101) was inspired by bismuth phenolate metallodrugs, and could be synthesized entirely from nonhazardous or edible reagents under ambient aqueous conditions, enabling simple scale-up. Reagent-grade and affordable dietary supplement-grade ellagic acid was sourced from tree bark and pomegranate hulls, respectively. Biocompatibility and colloidal stability were confirmed by in vitro assays. The material exhibits remarkable chemical stability for a bioinspired MOF (pH = 2-14, hydrothermal conditions, heated organic solvents, biological media, SO2 and H2S), attributed to the strongly chelating phenolates. A total H2S uptake of 15.95 mmol g-1 was recorded, representing one of the highest H2S capacities for a MOF, where polysulfides are formed inside the pores of the material. Phenolic phytochemicals remain largely unexplored as linkers for MOF synthesis, opening new avenues to design stable, eco-friendly, scalable, and low-cost MOFs for diverse applications, including drug delivery
Microcavity-like exciton-polaritons can be the primary photoexcitation in bare organic semiconductors.
Strong-coupling between excitons and confined photonic modes can lead to the formation of new quasi-particles termed exciton-polaritons which can display a range of interesting properties such as super-fluidity, ultrafast transport and Bose-Einstein condensation. Strong-coupling typically occurs when an excitonic material is confided in a dielectric or plasmonic microcavity. Here, we show polaritons can form at room temperature in a range of chemically diverse, organic semiconductor thin films, despite the absence of an external cavity. We find evidence of strong light-matter coupling via angle-dependent peak splittings in the reflectivity spectra of the materials and emission from collective polariton states. We additionally show exciton-polaritons are the primary photoexcitation in these organic materials by directly imaging their ultrafast (5 × 106 m s-1), ultralong (~270 nm) transport. These results open-up new fundamental physics and could enable a new generation of organic optoelectronic and light harvesting devices based on cavity-free exciton-polaritons.EPSRC (EP/R025517/1),
EPSRC (EP/M025330/1),
ERC Horizon 2020 (grant agreements No 670405 and No 758826),
ERC (ERC-2014-STG H2020 639088),
Netherlands Organisation for Scientific Research,
Swedish Research Council (VR, 2014-06948),
Knut and Alice Wallenberg Foundation 3DEM-NATUR (no. 2012.0112),
Royal Commission for the Exhibition of 1851,
CNRS (France),
US Department of Energy, Office of Science, Basic Energy Sciences, CPIMS Program, Early Career Research Program (DE-SC0019188)
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