Direct Synthesis of Nano-Ferrierite along the 10-Ring-Channel Direction Boosts Their Catalytic Behavior

[EN] Ferrierite zeolites with nanosized crystals and external surface areas higher than 250m(2)g(-1) have been prepared at relatively low synthesis temperature (120 degrees C) by means of the collaborative effect of two organic structure directing agents (OSDA). In this way, hierarchical porosity is achieved without the use of post-synthesis treatments that usually involve leaching of Tatoms and solid loss. Adjusting the synthesis conditions it is possible to decrease the crystallite size in the directions of the 8- and 10-ring channels, [010] and [001] respectively, reducing their average pore length to 10-30nm and increasing the number of pores accessible. The small crystal size of the nano-ferrierites results in an improved accessibility of reactants to the catalytic active centers and enhanced product diffusion, leading to higher conversion and selectivity with lower deactivation rates for the oligomerization of 1-pentene into longer-chain olefins.This work has been supported by the European Union through the European Research Council (ERC-AdG-2014-671093, SynCatMatch) the Spanish government through the "Severo Ochoa Program" (SEV-2016-0683) and CTQ2015-70126-R, and by the Fundacion Ramon Areces through a research project within the "Life and Materials Sciences" program. M.R.D.-R. acknowledges "La Caixa-Severo Ochoa" International PhD Fellowships (call 2015). The Electron Microscopy Service of the Universitat Politecnica de Valencia is acknowledged for its help in sample characterization. We thank Dr. Manuel Moliner for helpful discussions.Margarit Benavent, VJ.; Díaz-Rey, MDR.; Navarro Villalba, MT.; Martínez, C.; Corma Canós, A. (2018). Direct Synthesis of Nano-Ferrierite along the 10-Ring-Channel Direction Boosts Their Catalytic Behavior. Angewandte Chemie International Edition. 57(13):3459-3463. https://doi.org/10.1002/anie.201711418S34593463571

Femto-to nanosecond photodynamics of Nile Red in metal-ion exchanged faujasites

[EN] We report on the photodynamics of Nile Red (NR) interacting with faujasite (NaY)-type zeolites having different Na/Al ratios and charge balancing metals (Li+, Mg2+, and Cs+) in dichloromethane (DCM) suspensions. The encapsulation of NR in these materials leads to the formation of different populations, reflected in H- and J-aggregates, monomers, and surface adsorbed species. Due to the interaction of the dye with both the Bronsted and Lewis sites of the zeolite, a bathochromic shift is observed in the steady-state diffuse transmittance and emission spectra. The relative contribution of each population is affected by the Na/Al ratio and the nature of the doping metal ion. These findings are further explored by femtoto nanosecond time-resolved emission experiments, where a multi-exponential behaviour is observed for the excited samples. The fluorescence lifetimes range from similar to 100 ps to similar to 2 ns. They are assigned to the emission from H- and J-aggregates and monomers. At low Na/Al ratios, we observed an increase in the fluorescence time constants which is explained in terms of H-bonds formation between NR and the zeolite framework, while the change in the emission lifetimes for the metal ion exchanged zeolites is due to the variation of the properties (size and polarization ability) of the exchanged cation. An ultrafast formation (similar to 200 fs) of a charge-separated state (CS) followed by a vibrational cooling (similar to 1-2 ps) are observed in the fluorescence up-conversion transients. These results indicate a strong interaction between NR and the studied zeolites and may help for the design of metal ion sensors and for a better understanding of nanocatalysis. (C) 2017 Elsevier Inc. All rights reserved.This work was supported by the JCCM and MINECO through projects: PEII-2014-003-P, Consolider Ingenio 2010 (CSD2009-0050, MULTICAT), and MAT2014-57646-P. A. Corma and M.T. Navarro thank the MINECO (Severo Ochoa program SEV-2012-0267 and MAT2015-71842-P) for financial support.Di Nunzio, MR.; Caballero-Mancebo, E.; Martin, C.; Cohen, B.; Navarro Villalba, MT.; Corma Canós, A.; Douhal, A. (2018). Femto-to nanosecond photodynamics of Nile Red in metal-ion exchanged faujasites. Microporous and Mesoporous Materials. 256:214-226. https://doi.org/10.1016/j.micromeso.2017.08.011S21422625

Propene Production by Butene Cracking. Descriptors for Zeolite Catalysts

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Catalysis, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acscatal.0c02799[EN] Among the possible on-purpose technologies for propene production, direct conversion of butene-rich fractions to propene represents an attractive alternative to conventional routes such as steam cracking or fluid catalytic cracking. Here, we present an approach for designing an efficient ZSM-5-based catalyst for the selective cracking of butenes to propene by properly balancing diffusional and compositional effects. Instead of the large coffin-shaped ZSM-5 crystallites with very high Si/Al ratios generally reported, the optimal catalyst in terms of propene selectivity and catalyst life was found to be a ZSM-5 zeolite with a squared morphology, submicron-sized crystals (0.8 x 0.3 x 1.0 mu m), and a Si/Al molar ratio of around 300. For this crystal conformation, the short dimensions of both sinusoidal and straight channels facilitate propene diffusion and reduce its consumption in consecutive reactions, limiting the formation of C5+ oligomers and aromatics and maximizing propene selectivity. Coffin-type ZSM-5 crystals, with higher diffusional restrictions than square-shaped crystals, show faster catalyst deactivation than the latter, independently of the crystal size and Al content. However, among the ZSM-5 zeolite crystallites with a coffin morphology, the one presenting intergrowths on the (010) face, with a larger proportion of sinusoidal channels, shows a lower aromatic selectivity and deactivation rate, whereas the other two, with straight channels open to the clean (010) faces, favor the formation of aromatics by direct cyclization-dehydrogenation of oligomeric intermediates.This work has been supported by Saudi Aramco, by the Spanish Government-MICINN through "Severo Ochoa" (SEV-2016-0683) and RTI2018-101033-B-I00, and by Generalitat Valenciana (AICO/2019/060). We thank the Electron Microscopy Service of the UPV for their help in sample characterization.Del Campo Huertas, P.; Navarro Villalba, MT.; Shaikh, SK.; Khokhar, MD.; Aljumah, F.; Martínez, C.; Corma Canós, A. (2020). Propene Production by Butene Cracking. Descriptors for Zeolite Catalysts. ACS Catalysis. 10(20):11878-11891. https://doi.org/10.1021/acscatal.0c02799S11878118911020Agency, I. E. The Future of Petrochemicals: Towards More Sustainable Plastics and Fertilisers; IEA Publications: France, 2018, http://www.iea.org (accessed February 2020).Sholl, D. S., & Lively, R. P. (2016). Seven chemical separations to change the world. Nature, 532(7600), 435-437. doi:10.1038/532435aBereciartua, P. J., Cantín, Á., Corma, A., Jordá, J. L., Palomino, M., Rey, F., … Casty, G. L. (2017). Control of zeolite framework flexibility and pore topology for separation of ethane and ethylene. Science, 358(6366), 1068-1071. doi:10.1126/science.aao0092Jordá, J. L., Rey, F., Sastre, G., Valencia, S., Palomino, M., Corma, A., … Rodríguez-Velamazán, J. A. (2013). Synthesis of a Novel Zeolite through a Pressure-Induced Reconstructive Phase Transition Process. Angewandte Chemie International Edition, 52(40), 10458-10462. doi:10.1002/anie.201305230Gutiérrez-Sevillano, J. J., Dubbeldam, D., Rey, F., Valencia, S., Palomino, M., Martín-Calvo, A., & Calero, S. (2010). Analysis of the ITQ-12 Zeolite Performance in Propane−Propylene Separations Using a Combination of Experiments and Molecular Simulations. The Journal of Physical Chemistry C, 114(35), 14907-14914. doi:10.1021/jp101744kPalomino, M., Cantín, A., Corma, A., Leiva, S., Rey, F., & Valencia, S. (2007). Pure silica ITQ-32 zeolite allows separation of linear olefins from paraffins. Chem. Commun., (12), 1233-1235. doi:10.1039/b700358gBlay, V., Miguel, P. J., & Corma, A. (2017). Theta-1 zeolite catalyst for increasing the yield of propene when cracking olefins and its potential integration with an olefin metathesis unit. Catalysis Science & Technology, 7(24), 5847-5859. doi:10.1039/c7cy01502jCorma, A., Corresa, E., Mathieu, Y., Sauvanaud, L., Al-Bogami, S., Al-Ghrami, M. S., & Bourane, A. (2017). Crude oil to chemicals: light olefins from crude oil. Catalysis Science & Technology, 7(1), 12-46. doi:10.1039/c6cy01886fChen, J. Q., Bozzano, A., Glover, B., Fuglerud, T., & Kvisle, S. (2005). Recent advancements in ethylene and propylene production using the UOP/Hydro MTO process. Catalysis Today, 106(1-4), 103-107. doi:10.1016/j.cattod.2005.07.178Al-Khattaf, S. S.; Palani, A.; Bhuiyan, T. I.; Shaikh, S.; Akhtar, M. N.; Aitani, A. M.; Al-Yami, M. A. Dual Catalyst System for Propene Production. U.S. Patent 10,052,618 B2, 2018.Alshafei, F. H.; Khokhar, M. D.; Sulais, N. A.; Alalouni, M. R.; Shaikh, S. K. Multiple-Stage Catalyst System for Self-Metathesis with Controlled Isomerization and Cracking. U.S. Patent 2018/0,208,524 A1, 2018.Khokhar, M. D.; Alshafei, F. H.; Sulais, N. A.; Shaikh, S. K.; Abudawoud, R. H. Dual Catalyst Processes and Systems for Propene Production. U.S. Patent 10,329,225 B2, 2019.Shaikh, S.; Jamal, A.; Zhang, Z. Systems and Methods for Producing Propene. U.S. Patent 9,834,497 B2, 2017.Arudra, P., Bhuiyan, T. I., Akhtar, M. N., Aitani, A. M., Al-Khattaf, S. S., & Hattori, H. (2014). Silicalite-1 As Efficient Catalyst for Production of Propene from 1-Butene. ACS Catalysis, 4(11), 4205-4214. doi:10.1021/cs5009255Lin, L., Qiu, C., Zhuo, Z., Zhang, D., Zhao, S., Wu, H., … He, M. (2014). Acid strength controlled reaction pathways for the catalytic cracking of 1-butene to propene over ZSM-5. Journal of Catalysis, 309, 136-145. doi:10.1016/j.jcat.2013.09.011ZHAO, G., TENG, J., XIE, Z., JIN, W., YANG, W., CHEN, Q., & TANG, Y. (2007). Effect of phosphorus on HZSM-5 catalyst for C4-olefin cracking reactions to produce propylene. Journal of Catalysis, 248(1), 29-37. doi:10.1016/j.jcat.2007.02.027Blay, V., Epelde, E., Miravalles, R., & Perea, L. A. (2018). Converting olefins to propene: Ethene to propene and olefin cracking. Catalysis Reviews, 60(2), 278-335. doi:10.1080/01614940.2018.1432017Shi, J., Wang, Y., Yang, W., Tang, Y., & Xie, Z. (2015). Recent advances of pore system construction in zeolite-catalyzed chemical industry processes. Chemical Society Reviews, 44(24), 8877-8903. doi:10.1039/c5cs00626kZhao, G.-L., Teng, J.-W., Xie, Z.-K., Yang, W.-M., Chen, Q.-L., & Tang, Y. (2007). Catalytic cracking reactions of C4-olefin over zeolites H-ZSM-5, H-mordenite and H-SAPO-34. Studies in Surface Science and Catalysis, 1307-1312. doi:10.1016/s0167-2991(07)80992-xZhu, X., Liu, S., Song, Y., & Xu, L. (2005). Catalytic cracking of C4 alkenes to propene and ethene: Influences of zeolites pore structures and Si/Al2 ratios. Applied Catalysis A: General, 288(1-2), 134-142. doi:10.1016/j.apcata.2005.04.050Xu, G., Zhu, X., Xie, S., Li, X., Liu, S., & Xu, L. (2009). 1-Butene Cracking to Propene on High Silica HMCM-22: Relations Between Product Distribution and Feed Conversion Under Various Temperatures. Catalysis Letters, 130(1-2), 204-210. doi:10.1007/s10562-009-9864-7Zhu, X., Liu, S., Song, Y., Xie, S., & Xu, L. (2005). Catalytic cracking of 1-butene to propene and ethene on MCM-22 zeolite. Applied Catalysis A: General, 290(1-2), 191-199. doi:10.1016/j.apcata.2005.05.028Zhao, G., Teng, J., Zhang, Y., Xie, Z., Yue, Y., Chen, Q., & Tang, Y. (2006). Synthesis of ZSM-48 zeolites and their catalytic performance in C4-olefin cracking reactions. Applied Catalysis A: General, 299, 167-174. doi:10.1016/j.apcata.2005.10.022SAZAMA, P., DEDECEK, J., GABOVA, V., WICHTERLOVA, B., SPOTO, G., & BORDIGA, S. (2008). Effect of aluminium distribution in the framework of ZSM-5 on hydrocarbon transformation. Cracking of 1-butene. Journal of Catalysis, 254(2), 180-189. doi:10.1016/j.jcat.2007.12.005Epelde, E., Gayubo, A. G., Olazar, M., Bilbao, J., & Aguayo, A. T. (2014). Modified HZSM-5 zeolites for intensifying propylene production in the transformation of 1-butene. Chemical Engineering Journal, 251, 80-91. doi:10.1016/j.cej.2014.04.060Ibáñez, M., Epelde, E., Aguayo, A. T., Gayubo, A. G., Bilbao, J., & Castaño, P. (2017). Selective dealumination of HZSM-5 zeolite boosts propylene by modifying 1-butene cracking pathway. Applied Catalysis A: General, 543, 1-9. doi:10.1016/j.apcata.2017.06.008Epelde, E., Gayubo, A. G., Olazar, M., Bilbao, J., & Aguayo, A. T. (2014). Intensifying Propylene Production by 1-Butene Transformation on a K Modified HZSM-5 Zeolite-Catalyst. Industrial & Engineering Chemistry Research, 53(12), 4614-4622. doi:10.1021/ie500082vEpelde, E., Santos, J. I., Florian, P., Aguayo, A. T., Gayubo, A. G., Bilbao, J., & Castaño, P. (2015). Controlling coke deactivation and cracking selectivity of MFI zeolite by H3PO4 or KOH modification. Applied Catalysis A: General, 505, 105-115. doi:10.1016/j.apcata.2015.07.022Zhu, X., Liu, S., Song, Y., & Xu, L. (2005). Butene Catalytic Cracking to Propene and Ethene over Potassium Modified ZSM-5 Catalysts. Catalysis Letters, 103(3-4), 201-210. doi:10.1007/s10562-005-7155-5BLASCO, T., CORMA, A., & MARTINEZTRIGUERO, J. (2006). Hydrothermal stabilization of ZSM-5 catalytic-cracking additives by phosphorus addition. Journal of Catalysis, 237(2), 267-277. doi:10.1016/j.jcat.2005.11.011Lv, J., Hua, Z., Ge, T., Zhou, J., Zhou, J., Liu, Z., … Shi, J. (2017). Phosphorus modified hierarchically structured ZSM-5 zeolites for enhanced hydrothermal stability and intensified propylene production from 1-butene cracking. Microporous and Mesoporous Materials, 247, 31-37. doi:10.1016/j.micromeso.2017.03.037Wang, Z., Jiang, G., Zhao, Z., Feng, X., Duan, A., Liu, J., … Gao, J. (2009). Highly Efficient P-Modified HZSM-5 Catalyst for the Coupling Transformation of Methanol and 1-Butene to Propene. Energy & Fuels, 24(2), 758-763. doi:10.1021/ef9009907XUE, N., CHEN, X., NIE, L., GUO, X., DING, W., CHEN, Y., … XIE, Z. (2007). Understanding the enhancement of catalytic performance for olefin cracking: Hydrothermally stable acids in P/HZSM-5. Journal of Catalysis, 248(1), 20-28. doi:10.1016/j.jcat.2007.02.022Li, C., Vidal-Moya, A., Miguel, P. J., Dedecek, J., Boronat, M., & Corma, A. (2018). Selective Introduction of Acid Sites in Different Confined Positions in ZSM-5 and Its Catalytic Implications. ACS Catalysis, 8(8), 7688-7697. doi:10.1021/acscatal.8b02112Gao, X., Tang, Z., Lu, G., Cao, G., Li, D., & Tan, Z. (2010). Butene catalytic cracking to ethylene and propylene on mesoporous ZSM-5 by desilication. Solid State Sciences, 12(7), 1278-1282. doi:10.1016/j.solidstatesciences.2010.04.020Mitchell, S., Boltz, M., Liu, J., & Pérez-Ramírez, J. (2017). Engineering of ZSM-5 zeolite crystals for enhanced lifetime in the production of light olefins via 2-methyl-2-butene cracking. Catalysis Science & Technology, 7(1), 64-74. doi:10.1039/c6cy01009aShi, J., Zhao, G., Teng, J., Wang, Y., & Xie, Z. (2018). Morphology control of ZSM-5 zeolites and their application in Cracking reaction of C4 olefin. Inorganic Chemistry Frontiers, 5(11), 2734-2738. doi:10.1039/c8qi00686eAl-Khattaf, S. S.; Palani, A.; Aitani, A. M. Catalytic Hydrocracking of Light Olefins. U.S. Patent 9,783,464 B2, 2017.Johnson, D. L.; Nariman, K. E.; Ware, R. A. Catalytic Production of Light Olefins Rich in Propene. U.S. Patent 6,222,087 B1, 2001.Wang, C., Zhang, L., Huang, X., Zhu, Y., Li, G. (Kevin), Gu, Q., … Ma, D. (2019). Maximizing sinusoidal channels of HZSM-5 for high shape-selectivity to p-xylene. Nature Communications, 10(1). doi:10.1038/s41467-019-12285-4Fu, D., Heijden, O., Stanciakova, K., Schmidt, J. E., & Weckhuysen, B. M. (2020). Disentangling Reaction Processes of Zeolites within Single‐Oriented Channels. Angewandte Chemie International Edition, 59(36), 15502-15506. doi:10.1002/anie.201916596Xomeritakis, G., & Tsapatsis, M. (1999). Permeation of Aromatic Isomer Vapors through Oriented MFI-Type Membranes Made by Secondary Growth. Chemistry of Materials, 11(4), 875-878. doi:10.1021/cm9811343Van der Pol, A. J. H. P., & van Hooff, J. H. C. (1992). Parameters affecting the synthesis of titanium silicalite 1. Applied Catalysis A: General, 92(2), 93-111. doi:10.1016/0926-860x(92)80309-zTang, X., Zhou, H., Qian, W., Wang, D., Jin, Y., & Wei, F. (2008). High Selectivity Production of Propylene from n-Butene: Thermodynamic and Experimental Study Using a Shape Selective Zeolite Catalyst. Catalysis Letters, 125(3-4), 380-385. doi:10.1007/s10562-008-9564-8Rouquerol, J., Llewellyn, P., & Rouquerol, F. (2007). Is the bet equation applicable to microporous adsorbents? Characterization of Porous Solids VII - Proceedings of the 7th International Symposium on the Characterization of Porous Solids (COPS-VII), Aix-en-Provence, France, 26-28 May 2005, 49-56. doi:10.1016/s0167-2991(07)80008-5Zhang, X., Liu, D., Xu, D., Asahina, S., Cychosz, K. A., Agrawal, K. V., … Tsapatsis, M. (2012). Synthesis of Self-Pillared Zeolite Nanosheets by Repetitive Branching. Science, 336(6089), 1684-1687. doi:10.1126/science.1221111Choi, M., Na, K., Kim, J., Sakamoto, Y., Terasaki, O., & Ryoo, R. (2009). Stable single-unit-cell nanosheets of zeolite MFI as active and long-lived catalysts. Nature, 461(7261), 246-249. doi:10.1038/nature08288Liu, C., Kong, D., & Guo, H. (2014). The morphology control of zeolite ZSM-5 by regulating the polymerization degree of silicon and aluminum sources. Microporous and Mesoporous Materials, 193, 61-68. doi:10.1016/j.micromeso.2014.03.015Zhang, F.-Z., Fuji, M., & Takahashi, M. (2005). In Situ Growth of Continuous b-Oriented MFI Zeolite Membranes on Porous α-Alumina Substrates Precoated with a Mesoporous Silica Sublayer. Chemistry of Materials, 17(5), 1167-1173. doi:10.1021/cm048644jKox, M. H. F., Stavitski, E., & Weckhuysen, B. M. (2007). Nonuniform Catalytic Behavior of Zeolite Crystals as Revealed by In Situ Optical Microspectroscopy. Angewandte Chemie International Edition, 46(20), 3652-3655. doi:10.1002/anie.200700246Roeffaers, M. B. J., Ameloot, R., Baruah, M., Uji-i, H., Bulut, M., De Cremer, G., … De Vos, D. E. (2008). Morphology of Large ZSM-5 Crystals Unraveled by Fluorescence Microscopy. Journal of the American Chemical Society, 130(17), 5763-5772. doi:10.1021/ja7113147Roeffaers, M. B. J., Ameloot, R., Bons, A.-J., Mortier, W., De Cremer, G., de Kloe, R., … Sels, B. F. (2008). Relating Pore Structure to Activity at the Subcrystal Level for ZSM-5: An Electron Backscattering Diffraction and Fluorescence Microscopy Study. Journal of the American Chemical Society, 130(41), 13516-13517. doi:10.1021/ja8048767Koegler, J. H., van Bekkum, H., & Jansen, J. C. (1997). Growth model of oriented crystals of zeolite Si-ZSM-5. Zeolites, 19(4), 262-269. doi:10.1016/s0144-2449(97)00088-2Treps, L., Gomez, A., de Bruin, T., & Chizallet, C. (2020). Environment, Stability and Acidity of External Surface Sites of Silicalite-1 and ZSM-5 Micro and Nano Slabs, Sheets, and Crystals. ACS Catalysis, 10(5), 3297-3312. doi:10.1021/acscatal.9b05103Zeng, G., Chen, C., Li, D., Hou, B., & Sun, Y. (2013). Exposure of (001) planes and (011) planes in MFI zeolite. CrystEngComm, 15(18), 3521. doi:10.1039/c3ce40142aRoeffaers, M. B. J., Sels, B. F., Uji-i, H., Blanpain, B., L’hoëst, P., Jacobs, P. A., … De Vos, D. E. (2007). Space- and Time-Resolved Visualization of Acid Catalysis in ZSM-5 Crystals by Fluorescence Microscopy. Angewandte Chemie International Edition, 46(10), 1706-1709. doi:10.1002/anie.200604336Díaz, I., Kokkoli, E., Terasaki, O., & Tsapatsis, M. (2004). Surface Structure of Zeolite (MFI) Crystals. Chemistry of Materials, 16(25), 5226-5232. doi:10.1021/cm0488534Corma, A., & Orchillés, A. V. (2000). Current views on the mechanism of catalytic cracking. Microporous and Mesoporous Materials, 35-36, 21-30. doi:10.1016/s1387-1811(99)00205-xLi, J., Li, T., Ma, H., Sun, Q., Li, C., Ying, W., & Fang, D. (2018). Kinetics of coupling cracking of butene and pentene on modified HZSM-5 catalyst. Chemical Engineering Journal, 346, 397-405. doi:10.1016/j.cej.2018.04.061Ma, Y., Cai, D., Li, Y., Wang, N., Muhammad, U., Carlsson, A., … Wei, F. (2016). The influence of straight pore blockage on the selectivity of methanol to aromatics in nanosized Zn/ZSM-5: an atomic Cs-corrected STEM analysis study. RSC Advances, 6(78), 74797-74801. doi:10.1039/c6ra19073aWang, N., Sun, W., Hou, Y., Ge, B., Hu, L., Nie, J., … Wei, F. (2018). Crystal-plane effects of MFI zeolite in catalytic conversion of methanol to hydrocarbons. Journal of Catalysis, 360, 89-96. doi:10.1016/j.jcat.2017.12.024Sarazen, M. L., Doskocil, E., & Iglesia, E. (2016). Effects of Void Environment and Acid Strength on Alkene Oligomerization Selectivity. ACS Catalysis, 6(10), 7059-7070. doi:10.1021/acscatal.6b02128Bortnovsky, O., Sazama, P., & Wichterlova, B. (2005). Cracking of pentenes to C2–C4 light olefins over zeolites and zeotypes. Applied Catalysis A: General, 287(2), 203-213. doi:10.1016/j.apcata.2005.03.037Gobin, O. C., Reitmeier, S. J., Jentys, A., & Lercher, J. A. (2009). Comparison of the Transport of Aromatic Compounds in Small and Large MFI Particles. The Journal of Physical Chemistry C, 113(47), 20435-20444. doi:10.1021/jp907444cGobin, O. C., Reitmeier, S. J., Jentys, A., & Lercher, J. A. (2009). Diffusion pathways of benzene, toluene and p-xylene in MFI. Microporous and Mesoporous Materials, 125(1-2), 3-10. doi:10.1016/j.micromeso.2009.01.025DEROUANE, E. (1980). A novel effect of shape selectivity: Molecular traffic control in zeolite ZSM-5. Journal of Catalysis, 65(2), 486-489. doi:10.1016/0021-9517(80)90328-0Iwase, Y., Sakamoto, Y., Shiga, A., Miyaji, A., Motokura, K., Koyama, T., & Baba, T. (2012). Shape-Selective Catalysis Determined by the Volume of a Zeolite Cavity and the Reaction Mechanism for Propylene Production by the Conversion of Butene Using a Proton-Exchanged Zeolite. The Journal of Physical Chemistry C, 116(8), 5182-5196. doi:10.1021/jp212549jOno, Y., Kitagawa, H., & Sendoda, Y. (1987). Transformation of but-1-ene into aromatic hydrocarbons over ZSM-5 zeolites. Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 83(9), 2913. doi:10.1039/f19878302913Coelho, A., Caeiro, G., Lemos, M. A. N. D. A., Lemos, F., & Ribeiro, F. R. (2013). 1-Butene oligomerization over ZSM-5 zeolite: Part 1 – Effect of reaction conditions. Fuel, 111, 449-460. doi:10.1016/j.fuel.2013.03.066Aloise, A., Catizzone, E., Migliori, M., B.Nagy, J., & Giordano, G. (2017). Catalytic behavior in propane aromatization using GA-MFI catalyst. Chinese Journal of Chemical Engineering, 25(12), 1863-1870. doi:10.1016/j.cjche.2017.04.016Song, L., & Rees, L. V. C. (2000). Adsorption and diffusion of cyclic hydrocarbon in MFI-type zeolites studied by gravimetric and frequency-response techniques. Microporous and Mesoporous Materials, 35-36, 301-314. doi:10.1016/s1387-1811(99)00229-2Voorhies, A. (1945). Carbon Formation in Catalytic Cracking. Industrial & Engineering Chemistry, 37(4), 318-322. doi:10.1021/ie50424a010Fogler, H. S. Elements of Chemical Reaction Engineering; Prentice Hall Profesional: United States, 2006; Chapter 10, Section 10.7, p 717

Pt and Pd nanoparticles supported on structured materials as catalysts for the selective reductive amination of carbonyl compounds

[EN] Metal catalysts based on Pt and Pd nano-particles supported on structured microporous Beta zeolites and mesoporous MCM-41 materials, as well as specially designed gamma-Al(2)O(3) samples, were synthesized following a simple and economic procedure. Physico-chemical characterization of metal-composites (by XRD, IR spectroscopy, TEM, N(2) adsorption, ICP, among others) indicated that both Pt and Pd nano-particles were adequately supported and homogeneously dispersed on supports. These metal/solid acid composites were applied as efficient catalysts under mild reaction conditions in the selective reductive amination of ketones, a useful industrial reaction for the synthesis of substituted amines and N-heterocycles. Results obtained showed that Pt/Al-Beta catalyst possesses the best catalytic activity (TON = 1610, with amine selectivities >95%) superior to that observed with commercial Pt/C and Pt/Al(2)O(3) (TON approximate to 1000). Enhancements in Pt/Al-Beta samples were achieved by optimizing the Pt loading, and mainly the Si/Al molar ratio in solids. On the contrary, inferior catalytic activities were encountered with the Pt/Si-MCM-41 and Pt/Al-MCM-41 materials. The Pd incorporation on MCM-41 materials produced more active catalysts than the commercial Pd/C and Pd/Al(2)O(3) samples. Finally, the study of Pt/ and Pd/gamma-Al(2)O(3) materials demonstrated that the treatments of support prior to the metal impregnation and the posterior calcinations processes were essentials to obtain efficient catalysts. (C) 2011 Elsevier B.V. All rights reserved.Financial support by Ministerio de Ciencia e Innovación (MICINN) of Spain (CTQ-2008-06446), CSIC (PIE-200980I063), and COST Action CM0903 (UBIOCHEM) is gratefully acknowledged. Authors also thank M.Arribas for help in adsorption measurements.Domine, ME.; Hernández-Soto, MC.; Navarro Villalba, MT.; Pérez, Y. (2011). Pt and Pd nanoparticles supported on structured materials as catalysts for the selective reductive amination of carbonyl compounds. Catalysis Today. 172(1):13-20. https://doi.org/10.1016/j.cattod.2011.05.013S1320172

Pt and Pd nanoparticles supported on structured materials as catalysts for the selective reductive amination of carbonyl compounds

[EN] Metal catalysts based on Pt and Pd nano-particles supported on structured microporous Beta zeolites and mesoporous MCM-41 materials, as well as specially designed gamma-Al(2)O(3) samples, were synthesized following a simple and economic procedure. Physico-chemical characterization of metal-composites (by XRD, IR spectroscopy, TEM, N(2) adsorption, ICP, among others) indicated that both Pt and Pd nano-particles were adequately supported and homogeneously dispersed on supports. These metal/solid acid composites were applied as efficient catalysts under mild reaction conditions in the selective reductive amination of ketones, a useful industrial reaction for the synthesis of substituted amines and N-heterocycles. Results obtained showed that Pt/Al-Beta catalyst possesses the best catalytic activity (TON = 1610, with amine selectivities >95%) superior to that observed with commercial Pt/C and Pt/Al(2)O(3) (TON approximate to 1000). Enhancements in Pt/Al-Beta samples were achieved by optimizing the Pt loading, and mainly the Si/Al molar ratio in solids. On the contrary, inferior catalytic activities were encountered with the Pt/Si-MCM-41 and Pt/Al-MCM-41 materials. The Pd incorporation on MCM-41 materials produced more active catalysts than the commercial Pd/C and Pd/Al(2)O(3) samples. Finally, the study of Pt/ and Pd/gamma-Al(2)O(3) materials demonstrated that the treatments of support prior to the metal impregnation and the posterior calcinations processes were essentials to obtain efficient catalysts. (C) 2011 Elsevier B.V. All rights reserved.Financial support by Ministerio de Ciencia e Innovación (MICINN) of Spain (CTQ-2008-06446), CSIC (PIE-200980I063), and COST Action CM0903 (UBIOCHEM) is gratefully acknowledged. Authors also thank M.Arribas for help in adsorption measurements.Domine, ME.; Hernández-Soto, MC.; Navarro Villalba, MT.; Pérez, Y. (2011). Pt and Pd nanoparticles supported on structured materials as catalysts for the selective reductive amination of carbonyl compounds. Catalysis Today. 172(1):13-20. doi:10.1016/j.cattod.2011.05.013S1320172

Direct Dual-Template Synthesis of MWW Zeolite Monolayers

A two-dimensional zeolite with the topol. of MWW sheets has been obtained by direct synthesis with a combination of two org. structure-directing agents. The resultant material consists of approx. 70 % single and double layers and displays a well-structured external surface area of about 300 m2 g-1. The delaminated zeolite prepd. by means of this single-step synthetic route has a high delamination degree, and the structural integrity of the MWW layers is well preserved. The new zeolite material displayed excellent activity, selectivity, and stability when used as a catalyst for the alkylation of benzene with propylene and found to be superior to the catalysts that are currently used for producing cumene.Financial support by the Spanish Government-MINECO through "Severo Ochoa" (SEV 2012-0267), Consolider Ingenio 2010-Multicat, and MAT2012-31657 is acknowledged. M.E.M.-A. thanks MINECO for financial support through a pre-doctoral fellowship (BES-2013-066800).Margarit Benavent, VJ.; Martínez Armero, ME.; Navarro Villalba, MT.; Martínez, C.; Corma Canós, A. (2015). Direct Dual-Template Synthesis of MWW Zeolite Monolayers. Angewandte Chemie International Edition. 54(46):13724-13728. https://doi.org/10.1002/anie.201506822S1372413728544

Titanosilicate zeolite precursors for highly efficient oxidation reactions

[EN] Titanosilicate zeolites are catalysts of interest in the field of fine chemicals. However, the generation and accessibility of active sites in titanosilicate materials for catalyzing reactions with large molecules is still a challenge. Herein, we prepared titanosilicate zeolite precursors with open zeolitic structures, tunable pore sizes, and controllable Si/Ti ratios through a hydrothermal crystallization strategy by using quaternary ammonium templates. A series of quaternary ammonium ions are discovered as effective organic templates. The prepared amorphous titanosilicate zeolites with some zeolite framework structural order have extra-large micropores and abundant octahedrally coordinated isolated Ti species, which lead to a superior catalytic performance in the oxidative desulfurization of dibenzothiophene (DBT) and epoxidation of cyclohexene. It is anticipated that the amorphous prezeolitic titanosilicates will benefit the catalytic conversion of bulky molecules in a wide range of reaction processes.The authors thank the National Key Research and Development Program of China (Grant 2016YFB0701100), the National Natural Science Foundation of China (Grant 21621001, 21920102005 and 21835002), the 111 Project (B17020), the European Union through the European Research Council (grant ERC-AdG-2014-671093, SynCatMatch), and the Spanish Government through "Severo Ochoa" (SEV-2016-0683, MINECO) for supporting this work. The APS was operated for the U.S. DOE Office of Science by the Argonne National Laboratory, and the CLS@APS facilities (Sector 20) were supported by the U.S. DOE under contract no. DEAC02-06CH11357, and the Canadian Light Source and its funding partners. R. Bai acknowledges the China Scholarship Council for the financial support. Jose Gaona Miguelez is also acknowledged for technical help.Bai, R.; Navarro Villalba, MT.; Song, Y.; Zhang, T.; Zou, Y.; Feng, Z.; Zhang, P.... (2020). Titanosilicate zeolite precursors for highly efficient oxidation reactions. Chemical Science. 11(45):12341-12349. https://doi.org/10.1039/d0sc04603eS12341123491145Li, Y., & Yu, J. (2014). New Stories of Zeolite Structures: Their Descriptions, Determinations, Predictions, and Evaluations. Chemical Reviews, 114(14), 7268-7316. doi:10.1021/cr500010rCorma, A. (1995). Inorganic Solid Acids and Their Use in Acid-Catalyzed Hydrocarbon Reactions. Chemical Reviews, 95(3), 559-614. doi:10.1021/cr00035a006Corma, A. (1997). From Microporous to Mesoporous Molecular Sieve Materials and Their Use in Catalysis. Chemical Reviews, 97(6), 2373-2420. doi:10.1021/cr960406nGallego, E. M., Portilla, M. T., Paris, C., León-Escamilla, A., Boronat, M., Moliner, M., & Corma, A. (2017). «Ab initio» synthesis of zeolites for preestablished catalytic reactions. Science, 355(6329), 1051-1054. doi:10.1126/science.aal0121Clerici, M. G. (2000). Topics in Catalysis, 13(4), 373-386. doi:10.1023/a:1009063106954Bellussi, G., Millini, R., Pollesel, P., & Perego, C. (2016). Zeolite science and technology at Eni. New Journal of Chemistry, 40(5), 4061-4077. doi:10.1039/c5nj03498aSmit, B., & Maesen, T. L. M. (2008). Towards a molecular understanding of shape selectivity. Nature, 451(7179), 671-678. doi:10.1038/nature06552Jae, J., Tompsett, G. A., Foster, A. J., Hammond, K. D., Auerbach, S. M., Lobo, R. F., & Huber, G. W. (2011). Investigation into the shape selectivity of zeolite catalysts for biomass conversion. Journal of Catalysis, 279(2), 257-268. doi:10.1016/j.jcat.2011.01.019Groen, J. C., Zhu, W., Brouwer, S., Huynink, S. J., Kapteijn, F., Moulijn, J. A., & Pérez-Ramírez, J. (2006). Direct Demonstration of Enhanced Diffusion in Mesoporous ZSM-5 Zeolite Obtained via Controlled Desilication. Journal of the American Chemical Society, 129(2), 355-360. doi:10.1021/ja065737oBai, R., Sun, Q., Wang, N., Zou, Y., Guo, G., Iborra, S., … Yu, J. (2016). Simple Quaternary Ammonium Cations-Templated Syntheses of Extra-Large Pore Germanosilicate Zeolites. Chemistry of Materials, 28(18), 6455-6458. doi:10.1021/acs.chemmater.6b03179Corma, A., Díaz-Cabañas, M. J., Jordá, J. L., Martínez, C., & Moliner, M. (2006). High-throughput synthesis and catalytic properties of a molecular sieve with 18- and 10-member rings. Nature, 443(7113), 842-845. doi:10.1038/nature05238Tosheva, L., & Valtchev, V. P. (2005). Nanozeolites:  Synthesis, Crystallization Mechanism, and Applications. Chemistry of Materials, 17(10), 2494-2513. doi:10.1021/cm047908zAwala, H., Gilson, J.-P., Retoux, R., Boullay, P., Goupil, J.-M., Valtchev, V., & Mintova, S. (2015). Template-free nanosized faujasite-type zeolites. Nature Materials, 14(4), 447-451. doi:10.1038/nmat4173Bai, R., Song, Y., Li, Y., & Yu, J. (2019). Creating Hierarchical Pores in Zeolite Catalysts. Trends in Chemistry, 1(6), 601-611. doi:10.1016/j.trechm.2019.05.010Li, K., Valla, J., & Garcia-Martinez, J. (2013). Realizing the Commercial Potential of Hierarchical Zeolites: New Opportunities in Catalytic Cracking. ChemCatChem, 6(1), 46-66. doi:10.1002/cctc.201300345Schneider, D., Mehlhorn, D., Zeigermann, P., Kärger, J., & Valiullin, R. (2016). Transport properties of hierarchical micro–mesoporous materials. Chemical Society Reviews, 45(12), 3439-3467. doi:10.1039/c5cs00715aCundy, C. S., & Cox, P. A. (2005). The hydrothermal synthesis of zeolites: Precursors, intermediates and reaction mechanism. Microporous and Mesoporous Materials, 82(1-2), 1-78. doi:10.1016/j.micromeso.2005.02.016Feng, G., Cheng, P., Yan, W., Boronat, M., Li, X., Su, J.-H., … Yu, J. (2016). Accelerated crystallization of zeolites via hydroxyl free radicals. Science, 351(6278), 1188-1191. doi:10.1126/science.aaf1559Chawla, A., Linares, N., Li, R., García-Martínez, J., & Rimer, J. D. (2020). Tracking Zeolite Crystallization by Elemental Mapping. Chemistry of Materials, 32(7), 3278-3287. doi:10.1021/acs.chemmater.0c00572Corma, A., & Díaz-Cabañas, M. J. (2006). Amorphous microporous molecular sieves with different pore dimensions and topologies: Synthesis, characterization and catalytic activity. Microporous and Mesoporous Materials, 89(1-3), 39-46. doi:10.1016/j.micromeso.2005.09.028Li, R., Chawla, A., Linares, N., Sutjianto, J. G., Chapman, K. W., Martínez, J. G., & Rimer, J. D. (2018). Diverse Physical States of Amorphous Precursors in Zeolite Synthesis. Industrial & Engineering Chemistry Research, 57(25), 8460-8471. doi:10.1021/acs.iecr.8b01695Haw, K.-G., Gilson, J.-P., Nesterenko, N., Akouche, M., El Siblani, H., Goupil, J.-M., … Valtchev, V. (2018). Supported Embryonic Zeolites and their Use to Process Bulky Molecules. ACS Catalysis, 8(9), 8199-8212. doi:10.1021/acscatal.8b01936Akouche, M., Gilson, J.-P., Nesterenko, N., Moldovan, S., Chateigner, D., Siblani, H. E., … Valtchev, V. (2020). Synthesis of Embryonic Zeolites with Controlled Physicochemical Properties. Chemistry of Materials, 32(5), 2123-2132. doi:10.1021/acs.chemmater.9b05258Inagaki, S., Thomas, K., Ruaux, V., Clet, G., Wakihara, T., Shinoda, S., … Valtchev, V. (2014). Crystal Growth Kinetics as a Tool for Controlling the Catalytic Performance of a FAU-Type Basic Catalyst. ACS Catalysis, 4(7), 2333-2341. doi:10.1021/cs500153eCundy, C. S., & Cox, P. A. (2003). The Hydrothermal Synthesis of Zeolites:  History and Development from the Earliest Days to the Present Time. Chemical Reviews, 103(3), 663-702. doi:10.1021/cr020060iGrand, J., Talapaneni, S. N., Vicente, A., Fernandez, C., Dib, E., Aleksandrov, H. A., … Mintova, S. (2017). One-pot synthesis of silanol-free nanosized MFI zeolite. Nature Materials, 16(10), 1010-1015. doi:10.1038/nmat4941Dubray, F., Moldovan, S., Kouvatas, C., Grand, J., Aquino, C., Barrier, N., … Mintova, S. (2019). Direct Evidence for Single Molybdenum Atoms Incorporated in the Framework of MFI Zeolite Nanocrystals. Journal of the American Chemical Society, 141(22), 8689-8693. doi:10.1021/jacs.9b02589Carati, A., Flego, C., Berti, D., Millini, R., Stocchi, B., & Perego, C. (1999). Influence of synthesis media on the TS-1 Characteristics. Porous materials in environmentally friendly pocesses, Proceedings of the 1st international FEZA conference, 45-52. doi:10.1016/s0167-2991(99)80195-5Perego, C., Carati, A., Ingallina, P., Mantegazza, M. A., & Bellussi, G. (2001). Production of titanium containing molecular sieves and their application in catalysis. Applied Catalysis A: General, 221(1-2), 63-72. doi:10.1016/s0926-860x(01)00797-9Parker, W. O., & Millini, R. (2006). Ti Coordination in Titanium Silicalite-1. Journal of the American Chemical Society, 128(5), 1450-1451. doi:10.1021/ja0576785Grosso-Giordano, N. A., Hoffman, A. S., Boubnov, A., Small, D. W., Bare, S. R., Zones, S. I., & Katz, A. (2019). Dynamic Reorganization and Confinement of TiIV Active Sites Controls Olefin Epoxidation Catalysis on Two-Dimensional Zeotypes. Journal of the American Chemical Society, 141(17), 7090-7106. doi:10.1021/jacs.9b02160Bai, R., Sun, Q., Song, Y., Wang, N., Zhang, T., Wang, F., … Yu, J. (2018). Intermediate-crystallization promoted catalytic activity of titanosilicate zeolites. Journal of Materials Chemistry A, 6(18), 8757-8762. doi:10.1039/c8ta01960fMartens, J. A., Buskens, P., Jacobs, P. A., van der Pol, A., van Hooff, J. H. C., Ferrini, C., … van Bekkum, H. (1993). Hydroxylation of phenol with hydrogen peroxide on EUROTS-1 catalyst. Applied Catalysis A: General, 99(1), 71-84. doi:10.1016/0926-860x(93)85040-vZHANG, X., WANG, Y., & XIN, F. (2006). Coke deposition and characterization on titanium silicalite-1 catalyst in cyclohexanone ammoximation. Applied Catalysis A: General, 307(2), 222-230. doi:10.1016/j.apcata.2006.03.050Fan, W., Duan, R.-G., Yokoi, T., Wu, P., Kubota, Y., & Tatsumi, T. (2008). Synthesis, Crystallization Mechanism, and Catalytic Properties of Titanium-Rich TS-1 Free of Extraframework Titanium Species. Journal of the American Chemical Society, 130(31), 10150-10164. doi:10.1021/ja7100399Xu, L., Huang, D.-D., Li, C.-G., Ji, X., Jin, S., Feng, Z., … Wu, P. (2015). Construction of unique six-coordinated titanium species with an organic amine ligand in titanosilicate and their unprecedented high efficiency for alkene epoxidation. Chemical Communications, 51(43), 9010-9013. doi:10.1039/c5cc02321aBordiga, S., Bonino, F., Damin, A., & Lamberti, C. (2007). Reactivity of Ti(iv) species hosted in TS-1 towards H2O2–H2O solutions investigated by ab initio cluster and periodic approaches combined with experimental XANES and EXAFS data: a review and new highlights. Physical Chemistry Chemical Physics, 9(35), 4854. doi:10.1039/b706637fGleeson, 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/b005780kGuo, Q., Sun, K., Feng, Z., Li, G., Guo, M., Fan, F., & Li, C. (2012). A Thorough Investigation of the Active Titanium Species in TS-1 Zeolite by In Situ UV Resonance Raman Spectroscopy. Chemistry - A European Journal, 18(43), 13854-13860. doi:10.1002/chem.201201319Xu, W., Zhang, T., Bai, R., Zhang, P., & Yu, J. (2020). A one-step rapid synthesis of TS-1 zeolites with highly catalytically active mononuclear TiO6 species. Journal of Materials Chemistry A, 8(19), 9677-9683. doi:10.1039/c9ta13851jMoteki, T., & Okubo, T. (2013). From Charge Density Mismatch to a Simplified, More Efficient Seed-Assisted Synthesis of UZM-4. Chemistry of Materials, 25(13), 2603-2609. doi:10.1021/cm400727rZhu, D., Wang, L., Fan, D., Yan, N., Huang, S., Xu, S., … Liu, Z. (2020). A Bottom‐Up Strategy for the Synthesis of Highly Siliceous Faujasite‐Type Zeolite. Advanced Materials, 32(26), 2000272. doi:10.1002/adma.202000272Pichat, P., Franco-Parra, C., & Barthomeuf, D. (1975). Infra-red structural study of various type L zeolites. Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 71(0), 991. doi:10.1039/f19757100991Wang, X., Li, G., Wang, W., Jin, C., & Chen, Y. (2011). Synthesis, characterization and catalytic performance of hierarchical TS-1 with carbon template from sucrose carbonization. Microporous and Mesoporous Materials, 142(2-3), 494-502. doi:10.1016/j.micromeso.2010.12.035Liu, M., Chang, Z., Wei, H., Li, B., Wang, X., & Wen, Y. (2016). Low-cost synthesis of size-controlled TS-1 by using suspended seeds: From screening to scale-up. Applied Catalysis A: General, 525, 59-67. doi:10.1016/j.apcata.2016.07.006Kumar, P., Gupta, J. K., Muralidhar, G., & Rao, T. S. R. P. (1998). Acidity studies on titanium silicalites-1 (TS-1) by ammonia adsorption using microcalorimetry. Studies in Surface Science and Catalysis, 463-472. doi:10.1016/s0167-2991(98)80320-0Ikuno, T., Chaikittisilp, W., Liu, Z., Iida, T., Yanaba, Y., Yoshikawa, T., … Okubo, T. (2015). Structure-Directing Behaviors of Tetraethylammonium Cations toward Zeolite Beta Revealed by the Evolution of Aluminosilicate Species Formed during the Crystallization Process. Journal of the American Chemical Society, 137(45), 14533-14544. doi:10.1021/jacs.5b11046Zecchina, A., Bordiga, S., Lamberti, C., Ricchiardi, G., Lamberti, C., Ricchiardi, G., … Mantegazza, M. (1996). Structural characterization of Ti centres in Ti-silicalite and reaction mechanisms in cyclohexanone ammoximation. Catalysis Today, 32(1-4), 97-106. doi:10.1016/s0920-5861(96)00075-2Li, C., Xiong, G., Xin, Q., Liu, J., Ying, P., Feng, Z., … Min, E. (1999). UV Resonance Raman Spectroscopic Identification of Titanium Atoms in the Framework of TS-1 Zeolite. Angewandte Chemie International Edition, 38(15), 2220-2222. doi:10.1002/(sici)1521-3773(19990802)38:153.0.co;2-gLi, C., Xiong, G., Liu, J., Ying, P., Xin, Q., & Feng, Z. (2001). Identifying Framework Titanium in TS-1 Zeolite by UV Resonance Raman Spectroscopy. The Journal of Physical Chemistry B, 105(15), 2993-2997. doi:10.1021/jp0042359Zhang, T., Zuo, Y., Liu, M., Song, C., & Guo, X. (2016). Synthesis of Titanium Silicalite-1 with High Catalytic Performance for 1-Butene Epoxidation by Eliminating the Extraframework Ti. ACS Omega, 1(5), 1034-1040. doi:10.1021/acsomega.6b00266Nguyen, H. K. D., Sankar, G., & Catlow, R. A. (2016). Reactivities study of titanium sites in titanosilicate frameworks by in situ XANES. Journal of Porous Materials, 24(2), 421-428. doi:10.1007/s10934-016-0275-zAnderson, R., Mountjoy, G., Smith, M. ., & Newport, R. . (1998). An EXAFS study of silica–titania sol–gels. Journal of Non-Crystalline Solids, 232-234, 72-79. doi:10.1016/s0022-3093(98)00373-1Tsuruta, Y., Satoh, T., Yoshida, T., Okumura, O., & Ueda, S. (1986). Studies on the Initial Product in the Synthesis of Zeolite A from Concentrated Solutions. New Developments in Zeolite Science and Technology, Proceedings of the 7th International Zeolite Conference, 1001-1007. doi:10.1016/s0167-2991(09)60975-7Walton, R. I., & O’Hare, D. (2001). An X-ray absorption fine structure study of amorphous precursors of a gallium silicate zeolite. Journal of Physics and Chemistry of Solids, 62(8), 1469-1479. doi:10.1016/s0022-3697(01)00063-

Modular organic structure-directing agents for the synthesis of zeolites

[EN] Organic structure-directing agents (OSDAs) are used to guide the formation of particular types of pores and channels during the synthesis of zeolites. We report that the use of highly versatile OSDAs based on phosphazenes has been successfully introduced for the synthesis of zeolites. This approach has made possible the synthesis of the elusive boggsite zeolite, which is formed by 10- and 12-ring intersecting channels. This topology and these pore dimensions present interesting opportunities for catalysis in reactions of industrial relevance.The authors thank the Spanish government (projects MAT2009-14528-C02-01, PLE2009-0054, and CONSOLIDER INGENIO 2010) and Generalitat Valenciana (Project Prometeo) for financial support. R. S. and N.V. thank UPV and CSIC for Programa de Formacion de Personal Investigador and Junta para la Ampliacion de Estudios predoctoral fellowships, respectively. Further details on the crystal structure may be obtained from the Fachinformationszentrum Karlsruhe, D-76344 Eggenstein-Leopoldshafen, Germany [fax: (+49) 7247-808-666; e-mail: [email protected]], on quoting the depository number CDS-422193.Simancas Coloma, R.; Dari, D.; Velamazan, N.; Navarro Villalba, MT.; Cantin Sanz, A.; Jorda Moret, JL.; Sastre Navarro, GI.... (2010). Modular organic structure-directing agents for the synthesis of zeolites. Science. 330(6008):1219-1222. https://doi.org/10.1126/science.119624012191222330600