Direct synthesis of the aluminosilicate form of the small pore CDO zeolite with novel OSDAs and the expanded polymorphs

[EN] A general procedure to synthesize the Al-containing layered CDO precursor (PreCDO) is presented, allowing its preparation under broad Si/Al molar ratios by using novel pyrrole-derived organic molecules as organic structure directing agents (OSDAs). The direct calcination of the PreCDO materials results in crystalline Al-containing small-pore CDO zeolites with controlled Al species in tetrahedral coordination. In contrast, mild acid treatments on the PreCDO materials allow achieving medium-pore interlayer expanded CDO zeolites (IEZ-CDO). These expanded zeolites show high crystallinity, high porosity and controlled Si/Al molar ratios. Finally, preliminary catalytic results indicate that the Al-containing CDO and IEZ-CDO samples show good activity and selectivity for the selective catalytic reduction (SCR) of NOx, and methanol-to-olefins (MTO) processes, respectively. (C) 2017 Elsevier Inc. All rights reserved.This work has been supported by the Spanish Government-MINECO through "Severo Ochoa" (SEV 2012-0267) and MAT2015-71261-R programs, and by the Fundacion Ramon Areces through a research project in "Life and Materials Sciences" program. The authors thank Isabel Millet for technical support.Martínez Franco, R.; Paris, C.; Martínez-Triguero, J.; Moliner Marin, M.; Corma Canós, A. (2017). Direct synthesis of the aluminosilicate form of the small pore CDO zeolite with novel OSDAs and the expanded polymorphs. Microporous and Mesoporous Materials. 246:147-157. https://doi.org/10.1016/j.micromeso.2017.03.014S14715724

Influence of Preparation Conditions on the Catalytic Performance of Mo/H-ZSM-5 for Methane Dehydroaromatization

[EN] Methane, the main component of natural gas, is an interesting source of chemicals and clean liquid fuels, and a promising alternative raw material to oil. Among the possible direct routes for methane conversion, its aromatization under non-oxidative conditions has received increasing attention, despite the low conversions obtained due to thermodynamic limitations, because of its high selectivity to benzene. Mo/H-ZSM-5, the first bifunctional zeolite-catalyst proposed for this reaction, is still considered as one of the most adequate and has been widely studied. Although the mono- or bifunctional nature of the MDA mechanism is still under debate, it is generally accepted that the Mo species activate the C-H bond in methane, producing the intermediates. These will aromatize on the Bronsted acid sites of the zeolite, whose pore dimensions will provide the shape selectivity needed for converting methane into benzene. An additional role of the zeolite's Bronsted acid sites is to promote the dispersion of the Mo oxide precursor. Here, we show the influence of the different preparation steps-metal incorporation, calcination and activation of the Mo/ZSM-5- on the metal dispersion and, therefore, on the activity and selectivity of the final catalyst. Metal dispersion is enhanced when the samples are calcined under dynamic conditions (DC) and activated in N-2, and the benefits are larger when the metal has been incorporated by solid state reaction (SSR), as observed by FESEM-BSE and H-2-TPR. This leads to catalysts with higher activity, increased aromatic selectivity and improved stability towards deactivation.This work has been supported by the Spanish Government-MICINN through "Severo Ochoa" (SEV-2016-0683, MINECO) and RTI2018-101033-B-I00 (MCIU/AEI/FEDER, UE), and by Generalitat Valenciana (AICO/2019/060). The authors thank B. Esparcia for technical assistance and the electron Microscopy Service of the UPV for their help in sample characterization.Portilla, MT.; Llopis, FJ.; Moliner Marin, M.; Martínez, C. (2021). Influence of Preparation Conditions on the Catalytic Performance of Mo/H-ZSM-5 for Methane Dehydroaromatization. Applied Sciences. 11(12):1-17. https://doi.org/10.3390/app11125465S117111

Improving the catalytic performance of SAPO-18 for the methanol-to-olefins (MTO) reaction by controlling the Si distribution and crystal size

[EN] The physico-chemical properties of the small pore SAPO-18 zeotype have been controlled by properly selecting the organic molecules acting as organic structure directing agents (OSDAs). The two organic molecules selected to attempt the synthesis of the SAPO-18 materials were N,N-diisopropylethylamine (DIPEA) and N,N-dimethyl-3,5-dimethylpiperidinium (DMDMP). On the one hand, DIPEA allows small crystal sizes (0.1-0.3 mu m) to be attained with limited silicon distributions when the silicon content in the synthesis gel is high (Si/TO2 similar to 0.8). On the other hand, the use of DMDMP directs the formation of larger crystallites (0.9-1.0 mu m) with excellent silicon distributions, even when the silicon content in the synthesis media is high (Si/TO2 similar to 0.8). It is worth noting that this is the first description of the use of DMDMP as OSDA for the synthesis of the SAPO-18 material, revealing not only the excellent directing role of this OSDA in stabilizing the large cavities present in the SAPO-18 structure, but also its role in selectively placing the silicon atoms in isolated framework positions. The synthesized SAPO-18 materials have been characterized by different techniques, such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), N-2 adsorption, solid state NMR, and ammonia temperature programmed desorption (NH3-TPD). Finally, their catalytic activity has been evaluated for the methanol-to-olefin (MTO) process at different reaction temperatures (350 and 400 degrees C), revealing that the SAPO-18 catalysts with optimized silicon distributions and crystal sizes show excellent catalytic properties for the MTO reaction. These optimized SAPO-18 materials present improved catalyst lifetimes compared to standard SAPO-34 and SSZ-39 catalysts, even when tested at low reaction temperatures (i.e. 350 degrees C).Financial support by the Spanish Government-MINECO through “Severo Ochoa” (SEV 2012-0267), MAT2015-71261-R, and CTQ2015-68951-C3-1-R; by the European Union through ERC-AdG-2014-671093 (SynCatMatch); and by the Generalitat Valenciana through the Prometeo program (PROMETEOII/2013/011) is acknowledged.Martínez Franco, R.; Li, Z.; Martínez Triguero, LJ.; Moliner Marin, M.; Corma Canós, A. (2016). Improving the catalytic performance of SAPO-18 for the methanol-to-olefins (MTO) reaction by controlling the Si distribution and crystal size. Catalysis Science and Technology. 6(8):2796-2806. https://doi.org/10.1039/C5CY02298CS2796280668Chen, D., Moljord, K., & Holmen, A. (2012). A methanol to olefins review: Diffusion, coke formation and deactivation on SAPO type catalysts. Microporous and Mesoporous Materials, 164, 239-250. doi:10.1016/j.micromeso.2012.06.046Tian, P., Wei, Y., Ye, M., & Liu, Z. (2015). Methanol to Olefins (MTO): From Fundamentals to Commercialization. ACS Catalysis, 5(3), 1922-1938. doi:10.1021/acscatal.5b00007Moliner, M., Martínez, C., & Corma, A. (2013). Synthesis Strategies for Preparing Useful Small Pore Zeolites and Zeotypes for Gas Separations and Catalysis. Chemistry of Materials, 26(1), 246-258. doi:10.1021/cm4015095Lok, B. M., Messina, C. A., Patton, R. L., Gajek, R. T., Cannan, T. R., & Flanigen, E. M. (1984). Silicoaluminophosphate molecular sieves: another new class of microporous crystalline inorganic solids. Journal of the American Chemical Society, 106(20), 6092-6093. doi:10.1021/ja00332a063Chen, 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.2005.07.178Stöcker, M. (1999). Methanol-to-hydrocarbons: catalytic materials and their behavior. Microporous and Mesoporous Materials, 29(1-2), 3-48. doi:10.1016/s1387-1811(98)00319-9M. Stöcker , Zeolites and Catalysis, Wiley-VCH Verlag GmbH & Co. KGaA, 2010, pp. 687–711Hereijgers, B. P. C., Bleken, F., Nilsen, M. H., Svelle, S., Lillerud, K.-P., Bjørgen, M., … Olsbye, U. (2009). Product shape selectivity dominates the Methanol-to-Olefins (MTO) reaction over H-SAPO-34 catalysts. Journal of Catalysis, 264(1), 77-87. doi:10.1016/j.jcat.2009.03.009Song, W., Haw, J. F., Nicholas, J. B., & Heneghan, C. S. (2000). Methylbenzenes Are the Organic Reaction Centers for Methanol-to-Olefin Catalysis on HSAPO-34. Journal of the American Chemical Society, 122(43), 10726-10727. doi:10.1021/ja002195gWilson, S., & Barger, P. (1999). The characteristics of SAPO-34 which influence the conversion of methanol to light olefins. Microporous and Mesoporous Materials, 29(1-2), 117-126. doi:10.1016/s1387-1811(98)00325-4Dai, W., Wang, X., Wu, G., Guan, N., Hunger, M., & Li, L. (2011). Methanol-to-Olefin Conversion on Silicoaluminophosphate Catalysts: Effect of Brønsted Acid Sites and Framework Structures. ACS Catalysis, 1(4), 292-299. doi:10.1021/cs200016uDeimund, M. A., Schmidt, J. E., & Davis, M. E. (2015). Effect of Pore and Cage Size on the Formation of Aromatic Intermediates During the Methanol-to-Olefins Reaction. Topics in Catalysis, 58(7-9), 416-423. doi:10.1007/s11244-015-0384-yWendelbo, R., Akporiaye, D., Andersen, A., Dahl, I. M., & Mostad, H. B. (1996). Synthesis, characterization and catalytic testing of SAPO-18, MgAPO-18, and ZnAPO-18 in the MTO reaction. Applied Catalysis A: General, 142(2), L197-L207. doi:10.1016/0926-860x(96)00118-4Gayubo, A. G., Aguayo, A. T., Alonso, A., & Bilbao, J. (2007). Kinetic Modeling of the Methanol-to-Olefins Process on a Silicoaluminophosphate (SAPO-18) Catalyst by Considering Deactivation and the Formation of Individual Olefins. Industrial & Engineering Chemistry Research, 46(7), 1981-1989. doi:10.1021/ie061278oChen, J., Li, J., Wei, Y., Yuan, C., Li, B., Xu, S., … Liu, Z. (2014). Spatial confinement effects of cage-type SAPO molecular sieves on product distribution and coke formation in methanol-to-olefin reaction. Catalysis Communications, 46, 36-40. doi:10.1016/j.catcom.2013.11.016Álvaro-Muñoz, T., Márquez-Álvarez, C., & Sastre, E. (2015). Mesopore-Modified SAPO-18 with Potential Use as Catalyst for the MTO Reaction. Topics in Catalysis, 59(2-4), 278-291. doi:10.1007/s11244-015-0447-0Chen, J., Wright, P. A., Thomas, J. M., Natarajan, S., Marchese, L., Bradley, S. M., … Gai-Boyes, P. L. (1994). SAPO-18 Catalysts and Their Broensted Acid Sites. The Journal of Physical Chemistry, 98(40), 10216-10224. doi:10.1021/j100091a042Bhawe, Y., Moliner-Marin, M., Lunn, J. D., Liu, Y., Malek, A., & Davis, M. (2012). Effect of Cage Size on the Selective Conversion of Methanol to Light Olefins. ACS Catalysis, 2(12), 2490-2495. doi:10.1021/cs300558xDusselier, M., Deimund, M. A., Schmidt, J. E., & Davis, M. E. (2015). Methanol-to-Olefins Catalysis with Hydrothermally Treated Zeolite SSZ-39. ACS Catalysis, 5(10), 6078-6085. doi:10.1021/acscatal.5b01577Martín, N., Li, Z., Martínez-Triguero, J., Yu, J., Moliner, M., & Corma, A. (2016). Nanocrystalline SSZ-39 zeolite as an efficient catalyst for the methanol-to-olefin (MTO) process. Chemical Communications, 52(36), 6072-6075. doi:10.1039/c5cc09719cChen, J., Thomas, J. M., Wright, P. A., & Townsend, R. P. (1994). Silicoaluminophosphate number eighteen (SAPO-18): a new microporous solid acid catalyst. Catalysis Letters, 28(2-4), 241-248. doi:10.1007/bf00806053Hunger, M., Seiler, M., & Buchholz, A. (2001). Catalysis Letters, 74(1/2), 61-68. doi:10.1023/a:1016687014695Fan, D., Tian, P., Xu, S., Xia, Q., Su, X., Zhang, L., … Liu, Z. (2012). A novel solvothermal approach to synthesize SAPO molecular sieves using organic amines as the solvent and template. Journal of Materials Chemistry, 22(14), 6568. doi:10.1039/c2jm15281aAbdollahi, S., Ghavipour, M., Nazari, M., Behbahani, R. M., & Moradi, G. R. (2015). Effects of static and stirring aging on physiochemical properties of SAPO-18 and its performance in MTO process. Journal of Natural Gas Science and Engineering, 22, 245-251. doi:10.1016/j.jngse.2014.11.036Yuen, L.-T., Zones, S. I., Harris, T. V., Gallegos, E. J., & Auroux, A. (1994). Product selectivity in methanol to hydrocarbon conversion for isostructural compositions of AFI and CHA molecular sieves. Microporous Materials, 2(2), 105-117. doi:10.1016/0927-6513(93)e0039-jBleken, F., Bjørgen, M., Palumbo, L., Bordiga, S., Svelle, S., Lillerud, K.-P., & Olsbye, U. (2009). The Effect of Acid Strength on the Conversion of Methanol to Olefins Over Acidic Microporous Catalysts with the CHA Topology. Topics in Catalysis, 52(3), 218-228. doi:10.1007/s11244-008-9158-0Wu, L., Degirmenci, V., Magusin, P. C. M. M., Lousberg, N. J. H. G. M., & Hensen, E. J. M. (2013). Mesoporous SSZ-13 zeolite prepared by a dual-template method with improved performance in the methanol-to-olefins reaction. Journal of Catalysis, 298, 27-40. doi:10.1016/j.jcat.2012.10.029Martínez-Franco, R., Moliner, M., & Corma, A. (2014). Direct synthesis design of Cu-SAPO-18, a very efficient catalyst for the SCR of NOx. Journal of Catalysis, 319, 36-43. doi:10.1016/j.jcat.2014.08.005Wagner, P., Nakagawa, Y., Lee, G. S., Davis, M. E., Elomari, S., Medrud, R. C., & Zones, S. I. (2000). Guest/Host Relationships in the Synthesis of the Novel Cage-Based Zeolites SSZ-35, SSZ-36, and SSZ-39. Journal of the American Chemical Society, 122(2), 263-273. doi:10.1021/ja990722uYu, T., Wang, J., Shen, M., & Li, W. (2013). NH3-SCR over Cu/SAPO-34 catalysts with various acid contents and low Cu loading. Catalysis Science & Technology, 3(12), 3234. doi:10.1039/c3cy00453hKatada, N., Nouno, K., Lee, J. K., Shin, J., Hong, S. B., & Niwa, M. (2011). Acidic Properties of Cage-Based, Small-Pore Zeolites with Different Framework Topologies and Their Silicoaluminophosphate Analogues. The Journal of Physical Chemistry C, 115(45), 22505-22513. doi:10.1021/jp207894nSmith, R. L., Svelle, S., del Campo, P., Fuglerud, T., Arstad, B., Lind, A., … Anderson, M. W. (2015). CHA/AEI intergrowth materials as catalysts for the Methanol-to-Olefins process. Applied Catalysis A: General, 505, 1-7. doi:10.1016/j.apcata.2015.06.027Martín, N., Boruntea, C. R., Moliner, M., & Corma, A. (2015). Efficient synthesis of the Cu-SSZ-39 catalyst for DeNOx applications. Chemical Communications, 51(55), 11030-11033. doi:10.1039/c5cc03200hOpanasenko, M. V., Roth, W. J., & Čejka, J. (2016). Two-dimensional zeolites in catalysis: current status and perspectives. Catalysis Science & Technology, 6(8), 2467-2484. doi:10.1039/c5cy02079dKim, W., & Ryoo, R. (2014). Probing the Catalytic Function of External Acid Sites Located on the MFI Nanosheet for Conversion of Methanol to Hydrocarbons. Catalysis Letters, 144(7), 1164-1169. doi:10.1007/s10562-014-1274-

Synthesis of highly stable metal-containing extra-large-pore molecular sieves

[EN] The isomorphic substitution of two different metals (Mg and Co) within the framework of the ITQ-51 zeotype (IFO structure) using bulky aromatic proton sponges as organic structure-directing agents (OSDAs) has allowed the synthesis of different stable metal-containing extra-large-pore zeotypes with high pore accessibility and acidity. These metal-containing extra-large-pore zeolites, named MgITQ-51 and CoITQ-51, have been characterized by different techniques, such as powder X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry, UV-Vis spectroscopy, temperature programmed desorption of ammonia and Fourier transform infrared spectroscopy, to study their physico-chemical properties. The characterization confirms the preferential insertion of Mg and Co atoms within the crystalline structure of the ITQ-51 zeotype, providing high Bronsted acidity, and allowing their use as efficient heterogeneous acid catalysts in industrially relevant reactions involving bulky organic molecules.Financial support by the Spanish Government-MINECO through 'Severo Ochoa' (SEV 2012-0267), Consolider Ingenio 2010-Multicat and MAT2012-37160 is acknowledged. The European Union is also acknowledged by the SynCatMatch project (ERC-AdG-2014-671093).Martínez Franco, R.; Paris-Carrizo, CG.; Moliner Marin, M.; Corma Canós, A. (2016). Synthesis of highly stable metal-containing extra-large-pore molecular sieves. Philosophical Transactions A: Mathematical, Physical and Engineering Sciences. 374(2061). https://doi.org/10.1098/rsta.2015.0075S3742061Jiang, J., Yu, J., & Corma, A. (2010). Extra-Large-Pore Zeolites: Bridging the Gap between Micro and Mesoporous Structures. Angewandte Chemie International Edition, 49(18), 3120-3145. doi:10.1002/anie.200904016Moliner, M., Rey, F., & Corma, A. (2013). Towards the Rational Design of Efficient Organic Structure-Directing Agents for Zeolite Synthesis. Angewandte Chemie International Edition, 52(52), 13880-13889. doi:10.1002/anie.201304713Davis, M. E. (1997). The Quest For Extra-Large Pore, Crystalline Molecular Sieves. Chemistry - A European Journal, 3(11), 1745-1750. doi:10.1002/chem.19970031104Davis, M. E. (2002). Ordered porous materials for emerging applications. Nature, 417(6891), 813-821. doi:10.1038/nature00785Corma, A. (2003). State of the art and future challenges of zeolites as catalysts. Journal of Catalysis, 216(1-2), 298-312. doi:10.1016/s0021-9517(02)00132-xCorma, 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/nature05238Davis, M. E., Saldarriaga, C., Montes, C., Garces, J., & Crowdert, C. (1988). A molecular sieve with eighteen-membered rings. Nature, 331(6158), 698-699. doi:10.1038/331698a0Corma, A., & Davis, M. E. (2004). Issues in the Synthesis of Crystalline Molecular Sieves: Towards the Crystallization of Low Framework-Density Structures. ChemPhysChem, 5(3), 304-313. doi:10.1002/cphc.200300997Martinez-Franco, R., Moliner, M., Yun, Y., Sun, J., Wan, W., Zou, X., & Corma, A. (2013). Synthesis of an extra-large molecular sieve using proton sponges as organic structure-directing agents. Proceedings of the National Academy of Sciences, 110(10), 3749-3754. doi:10.1073/pnas.1220733110Staab, H. A., & Saupe, T. (1988). ?Proton Sponges? and the Geometry of Hydrogen Bonds: Aromatic Nitrogen Bases with Exceptional Basicities. Angewandte Chemie International Edition in English, 27(7), 865-879. doi:10.1002/anie.198808653Corma, A., Diaz-Cabanas, M. J., Jiang, J., Afeworki, M., Dorset, D. L., Soled, S. L., & Strohmaier, K. G. (2010). Extra-large pore zeolite (ITQ-40) with the lowest framework density containing double four- and double three-rings. Proceedings of the National Academy of Sciences, 107(32), 13997-14002. doi:10.1073/pnas.1003009107(s. f.). doi:10.1021/jp027447Martínez-Franco, R., Sun, J., Sastre, G., Yun, Y., Zou, X., Moliner, M., & Corma, A. (2014). Supra-molecular assembly of aromatic proton sponges to direct the crystallization of extra-large-pore zeotypes. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences, 470(2166), 20140107. doi:10.1098/rspa.2014.0107Man, P. P., Briend, M., Peltre, M. J., Lamy, A., Beaunier, P., & Barthomeuf, D. (1991). A topological model for the silicon incorporation in SAPO-37 molecular sieves: Correlations with acidity and catalysis. Zeolites, 11(6), 563-572. doi:10.1016/s0144-2449(05)80006-5Wilson ST Flanigen EM. 1986 Crystalline metal aluminophosphates . U.S. Patent 4 567 029.Corà, F., Saadoune, I., & Catlow, C. R. A. (2002). Lewis Acidity in Transition-Metal-Doped Microporous Aluminophosphates. Angewandte Chemie International Edition, 41(24), 4677-4680. doi:10.1002/anie.200290013Hartmann, M., & Kevan, L. (2002). Substitution of transition metal ions into aluminophosphates and silicoaluminophosphates: characterization and relation to catalysis. Research on Chemical Intermediates, 28(7-9), 625-695. doi:10.1163/15685670260469357Šponer, J., Čejka, J., Dědeček, J., & Wichterlová, B. (2000). Coordination and properties of cobalt in the molecular sieves CoAPO-5 and -11. Microporous and Mesoporous Materials, 37(1-2), 117-127. doi:10.1016/s1387-1811(99)00258-9Singh, P. S., Shaikh, R. A., Bandyopadhyay, R., & Rao, B. S. (1995). Synthesis of CoVPI-5 with bifunctional catalytic activity. Journal of the Chemical Society, Chemical Communications, (22), 2255. doi:10.1039/c39950002255Jhung, S. H., Jin, T., Kim, Y. H., & Chang, J.-S. (2008). Phase-selective crystallization of cobalt-incorporated aluminophosphate molecular sieves with large pore by microwave irradiation. Microporous and Mesoporous Materials, 109(1-3), 58-65. doi:10.1016/j.micromeso.2007.04.031Iton, L. E., Choi, I., Desjardins, J. A., & Maroni, V. A. (1989). Stabilization of Co (III) in aluminophosphate molecular sieve frameworks. Zeolites, 9(6), 535-538. doi:10.1016/0144-2449(89)90051-1Frache, A., Gianotti, E., & Marchese, L. (2003). Spectroscopic characterisation of microporous aluminophosphate materials with potential application in environmental catalysis. Catalysis Today, 77(4), 371-384. doi:10.1016/s0920-5861(02)00381-4Yu, T., Wang, J., Shen, M., & Li, W. (2013). NH3-SCR over Cu/SAPO-34 catalysts with various acid contents and low Cu loading. Catalysis Science & Technology, 3(12), 3234. doi:10.1039/c3cy00453hYang, X., Ma, H., Xu, Z., Xu, Y., Tian, Z., & Lin, L. (2007). Hydroisomerization of n-dodecane over Pt/MeAPO-11 (Me=Mg, Mn, Co or Zn) catalysts. Catalysis Communications, 8(8), 1232-1238. doi:10.1016/j.catcom.2006.11.00

Behavioral Health at School: Do Three Competences in Road Safety Education Impact the Protective Road Behaviors of Spanish Children?

Background: Education in road safety (also known as Road Safety Education¿RSE) constitutes, nowadays, an emergent approach for improving present and future road behaviors, aiming at taking action against the current, and concerning, state-of-affairs of traffic crashes, through a behavioral perspective. In the case of children, and despite their overrepresentation in traffic injury figures, RSE-based strategies for behavioral health in transportation remain a 'new' approach, whose impact still needs to be empirically tested. Objective: The aim of this study is to assess the impact of three key road safety skills of the Positive Attitudes, Risk perception and Knowledge of norms (PARK) model, addressed in RSE-based interventions, on the safe road behavior of Spanish children. Methods: For this cross-sectional study, a representative sample of 1930 (50.4% males and 49.6% females) Spanish children attending primary school, with a mean age of 10.1 (SD = 1.6) years, was gathered from 70 educational centers across all Spanish regions, through a national study on RSE and road safety. Results: Road safety skills show a positive relationship with children's self-reported safe behaviors on the road. However, the knowledge of traffic norms alone does not predict safe behaviors: it needs to be combined with risk perception and positive attitudes towards road safety. Furthermore, the degree of exposure to previous RSE interventions was shown to have an effect on the score obtained by children in each road safety skill; on the other hand, road misbehaviors observed in parents and peers had a negative impact on them. Conclusion: The outcomes of this study suggest that education in road safety is still a key process for the acquisition of safe habits, patterns and behaviors among young road user

MIMO throughput effectiveness for basic MIMO OTA compliance testing

During the March 2011 meeting of the CTIA MIMO OTA Subgroup (MOSG), the members agreed that the subgroup should first determine “what” aspects of a MIMO-capable device require evaluation; then the group should determine “how” to go about making these measurements. In subsequent meetings of MOSG, new yet-unnamed figures of merit were asked for in order to provide a solution to the carriers' requirements for LTE MIMO OTA evaluation. Furthermore, the December 2011 3GPP RAN4 status report on LTE MIMO OTA listed the evaluation of the use of statistical performance analysis in order to minimize test time and help ensure accurate performance assessment as an open issue. This contribution addresses these petitions by providing four new figures of merit, which could serve the purpose of evaluating the operators' top priorities for MIMO OTA compliance testing. The new figures of merit are MIMO Throughput Effectiveness (MTE), MIMO Device Throughput Effectiveness (MDTE), MIMO Throughput Gain (MTG), and MIMO Device Throughput Gain (MDTG). In this paper, MTE is evaluated using the recently available LTE MIMO OTA RR data from 3GPP

Rational direct synthesis methodology of very active and hydrothermally stable Cu-SAPO-34 molecular sieves for the SCR of NOx

A one-pot direct synthesis of Cu-SAPO-34 has been achieved that allows more than 90% yield in the material synthesis. By this method it is easy to control the Cu-loading in the Cu-SAPO-34. It is presented that a maximum in hydrothermal stability with very high activity for NOx SCR with NH3 is obtained for an optimum Cu loading.This work has been supported by Haldor-Topsoe, Consolider Ingenio 2010-Multicat, and UPV through PAID-06-11 (no. 1952). MM acknowledges to "Subprograma Ramon y Cajal" for the contract RYC-2011-08972.Martínez Franco, R.; Moliner Marin, M.; Franch Martí, C.; Kustov, A.; Corma Canós, A. (2012). Rational direct synthesis methodology of very active and hydrothermally stable Cu-SAPO-34 molecular sieves for the SCR of NOx. Applied Catalysis B: Environmental. 127:273-280. https://doi.org/10.1016/j.apcatb.2012.08.034S27328012

ITQ-39 zeolite, an efficient catalyst for the conversion of low value naphtha fractions into diesel fuel: The role of pore size on molecular diffusion and reactivity

[EN] ITQ-39, a multipore zeolite with interconnected 12- and 10-ring channel systems, effectively catalyzes the alkylation of two low value naphtha fractions for the production of diesel range alkylaromatics. A catalytic and molecular dynamics study allows us to conclude that its higher selectivity to the desired diesel fraction and, especially, its longer catalyst life as compared to beta or MCM-22, conventionally used as heterogeneous alkylation catalysts, are due to the combined contribution of its small nano-sized crystallites, moderate Bronsted acidity and unique framework topology. The small diffusion coefficients obtained for alkylaromatics on ITQ-39 as compared to those corresponding to the large pore beta zeolite evidence the significant diffusional problems of most of the reactants and products through the channels of the ITQ-39 structure. Thus, alkylation reactions on this zeolite seem to occur mainly on the most external acid sites (external surface, pore mouths), whereas the zeolite structure contributes positively by preventing undesired reactions to occur, which would result in lower selectivity to the monoalkylated products and in a faster catalyst deactivation.Financial support by the Spanish Government-MINECO through "Severo Ochoa" (SEV 2012-0267), Consolider Ingenio 2010-Multicat, MAT2012-37160 and MAT2012-31657, by the European Union through ERC-AdG-2014-671093 - SynCatMatch and by the Generalitat Valenciana through the Prometeo program (PROME-TEOII/2013/011) is acknowledged. Repsol is thanked for financial support and permission to publish these results. G.S. thanks ASIC-UPV for computing time. The Electron Microscopy Service of the UPV is acknowledged for their help in samples characterization.Martínez Armero, ME.; Moliner Marin, M.; Sastre Navarro, GI.; Rey Garcia, F.; Martínez, C.; Corma Canós, A. (2016). ITQ-39 zeolite, an efficient catalyst for the conversion of low value naphtha fractions into diesel fuel: The role of pore size on molecular diffusion and reactivity. Journal of Catalysis. 333:127-138. https://doi.org/10.1016/j.jcat.2015.10.024S12713833

Efficient Oligomerization of Pentene into Liquid Fuels on Nanocrystalline Beta Zeolites

[EN] Light alkenes oligomerization, performed in the presence of heterogeneous acid catalysts, is an interesting alternative for the production of clean liquid fuels. The process, when catalyzed by zeolites, is flexible and can be directed to the formation of oligomers in the gasoline, jet fuel, or diesel range by adjusting the reaction conditions and the zeolite's structure. Herein we show how reducing the crystal size of large-pore Beta zeolites down to 10-15 nm and controlling the number and strength distribution of their Bronsted acid sites leads to highly active and stable catalysts, selective to true oligomers within the naphtha and, especially, the diesel range. The shorter diffusion path lengths in the smaller crystallites and the reduced Bronsted acid site density of the two nanosized beta zeolites (10-15 nm) synthesized with Si/Al = 15 lead to 1-pentene conversion above 80% during the 6 h time on stream (TOS) at a space time (W/F) of 2.8 g.h.mol(-1). This value is higher than the olefin conversion obtained for a commercial nanobeta (30 nm) at a 3-fold space time of 9.1 g.h.mol(-1).Financial support by the Spanish Government-MINECO through "Severn Ochoa" (SEV-2016-0683), MAT2015-71261-R and CTQ2015-70126-R, by the Fundacion Ramon Areces through a research project within the "Life and Materials Sciences" program, and by the European Union through ERC-AdG-2014-671093-Syn-CatMatch is acknowledged. 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 their help in sample characterization.Díaz-Rey, MDR.; Paris-Carrizo, CG.; Martínez Franco, R.; Moliner Marin, M.; Martínez, C.; Corma Canós, A. (2017). Efficient Oligomerization of Pentene into Liquid Fuels on Nanocrystalline Beta Zeolites. ACS Catalysis. 7(9):6170-6178. https://doi.org/10.1021/acscatal.7b00817S617061787