Conversion of methanol to olefins: Stabilization of nanosized SAPO-34 by hydrothermal treatment

Nano-SAPO-34 zeolite catalyst (20 nm crystal size) has been stabilized by hydrothermal treatment. After steamed at high temperatures (T >= 550 degrees C), its textural properties and high lifetime during the reaction of methanol to olefins (MTO) are preserved, despite the decrease in acidity, even after months of contact with moisture. The stabilization effect is attributed to the migration of silicon to larger silicon islands in which the contribution of silicon on the edge is lower after steaming. Stabilization is not successful by a thermal treatment in air in the absence of water. Steaming at temperature >400 degrees C is required for achieving hydrothermal stabilization. A stability test for SAPO-34 in MTO reaction is proposed. (C) 2015 Elsevier Inc. All rights reserved.Financial support by the Spanish MINECO (Consolider Ingenio 2010-MULTICAT CSD2009-00050, MAT2012-37160, CTQ2012-37925-C03-1, Severo Ochoa SEV-2012-0267), and Generalitat Valenciana by the PROMETEO program (PROMETEOII/2013/011) is acknowledged. Z. Li acknowledges China Scholarship Council (CSC) for a fellowship. J. Yu thanks the Major International Joint Research Project of China for financial supports (Grant No. 21320102001). Support from Servicio de Microscopia Electronica (UPV) is also acknowledged.Li, Z.; Martínez Triguero, LJ.; Yu, J.; Corma Canós, A. (2015). Conversion of methanol to olefins: Stabilization of nanosized SAPO-34 by hydrothermal treatment. Journal of Catalysis. 329:379-388. https://doi.org/10.1016/j.jcat.2015.05.025S37938832

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. 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Methanol to olefins: activity and stability of nanosized SAPO-34 molecular sieves and control of selectivity by silicon distribution

[EN] Nano-SAPO-34 molecular sieves synthesized in a microwave environment with 20 nm crystal size showed a longer lifetime than SAPO-34 prepared by the conventional hydrothermal method in the reaction of methanol to olefins. It has been found that silicon distribution strongly affects the lifetime and selectivity. Thus, silicon at the border of the silicon islands gives a higher lifetime and lower C2/C3 ratio. This change in activity and selectivity is better explained in terms of different silicon distribution than by preferential diffusion of ethene through the 8MR pores and agrees with transition-state selectivity. The effects of equilibrium of olefins and deactivation by coke were isolated, showing that after full formation of the hydrocarbon pool, selectivity is independent of deactivation by coke.Financial support by the Spanish MINECO (MAT2012-37160, CSD2009-00050-CONSOLIDER/INGENIO 2010), and Generalitat Valenciana by the PROMETEO program is acknowledged. Z. Li acknowledges China Scholarship Council (CSC) for a fellowship. J. Yu thanks the support by the State Basic Research Project of China (Grant no. 2011CB808703) and the National Natural Science Foundation of China.Li, Z.; Martínez Triguero, LJ.; Concepción Heydorn, P.; Yu, J.; Corma Canós, A. (2013). Methanol to olefins: activity and stability of nanosized SAPO-34 molecular sieves and control of selectivity by silicon distribution. Physical Chemistry Chemical Physics. 15(35):14670-14680. https://doi.org/10.1039/c3cp52247dS14670146801535Bjørgen, M., Joensen, F., Spangsberg Holm, M., Olsbye, U., Lillerud, K.-P., & Svelle, S. (2008). Methanol to gasoline over zeolite H-ZSM-5: Improved catalyst performance by treatment with NaOH. Applied Catalysis A: General, 345(1), 43-50. doi:10.1016/j.apcata.2008.04.020Vennestrøm, P. N. R., Grill, M., Kustova, M., Egeblad, K., Lundegaard, L. F., Joensen, F., … Beato, P. (2011). 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Modelling methanol conversion to hydrocarbons: revision and testing of a simple kinetic model. Chemical Engineering Science, 45(5), 1161-1165. doi:10.1016/0009-2509(90)87109-6Chen, D., Rebo, H. P., Moljord, K., & Holmen, A. (1997). The role of coke deposition in the conversion of methanol to olefins over SAPO-34. Studies in Surface Science and Catalysis, 159-166. doi:10.1016/s0167-2991(97)80151-6Chen, D., Rebo, H. P., Moljord, K., & Holmen, A. (1999). Methanol Conversion to Light Olefins over SAPO-34. Sorption, Diffusion, and Catalytic Reactions. Industrial & Engineering Chemistry Research, 38(11), 4241-4249. doi:10.1021/ie9807046Svelle, S., Sommer, L., Barbera, K., Vennestrøm, P. N. R., Olsbye, U., Lillerud, K. P., … Beato, P. (2011). How defects and crystal morphology control the effects of desilication. Catalysis Today, 168(1), 38-47. doi:10.1016/j.cattod.2010.12.013Sazama, P., Wichterlova, B., Dedecek, J., Tvaruzkova, Z., Musilova, Z., Palumbo, L., … Gonsiorova, O. (2011). FTIR and 27Al MAS NMR analysis of the effect of framework Al- and Si-defects in micro- and micro-mesoporous H-ZSM-5 on conversion of methanol to hydrocarbons. Microporous and Mesoporous Materials, 143(1), 87-96. doi:10.1016/j.micromeso.2011.02.013Chen, D., Grønvold, A., Moljord, K., & Holmen, A. (2007). Methanol Conversion to Light Olefins over SAPO-34:  Reaction Network and Deactivation Kinetics. Industrial & Engineering Chemistry Research, 46(12), 4116-4123. doi:10.1021/ie0610748Dahl, I. M., Mostad, H., Akporiaye, D., & Wendelbo, R. (1999). Structural and chemical influences on the MTO reaction: a comparison of chabazite and SAPO-34 as MTO catalysts. Microporous and Mesoporous Materials, 29(1-2), 185-190. doi:10.1016/s1387-1811(98)00330-8Hereijgers, 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., Fu, H., & Haw, J. F. (2001). Supramolecular Origins of Product Selectivity for Methanol-to-Olefin Catalysis on HSAPO-34. Journal of the American Chemical Society, 123(20), 4749-4754. doi:10.1021/ja0041167Arstad, B., Nicholas, J. B., & Haw, J. F. (2004). Theoretical Study of the Methylbenzene Side-Chain Hydrocarbon Pool Mechanism in Methanol to Olefin Catalysis. Journal of the American Chemical Society, 126(9), 2991-3001. doi:10.1021/ja035923jZhou, H., Wang, Y., Wei, F., Wang, D., & Wang, Z. (2008). Kinetics of the reactions of the light alkenes over SAPO-34. Applied Catalysis A: General, 348(1), 135-141. doi:10.1016/j.apcata.2008.06.033Chen, 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.2012.06.046Wang, C.-M., Wang, Y.-D., & Xie, Z.-K. (2013). 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Synthesis of nano-SSZ-13 and its application in the reaction of methanol to olefins

[EN] Nanosized SSZ-13 has been obtained from a one-pot synthesis procedure with the addition of CTAB to the synthesis precursor solution. Nano-SSZ-13 zeolite showed high intracrystalline mesoporosity and compared to standard SSZ-13 presented a much longer lifetime and higher conversion capacity for the reaction of methanol to olefins. The improved properties were attributed to a more efficient utilization of micropores by easier diffusion of reactants and products and slower deactivation by coke. A higher C2/C3 ratio was found for nano-SSZ-13, pointing to a lower deactivation of the aromatics cycle of the hydrocarbon pool.Financial support by the Spanish Government-MINECO through “Severo Ochoa” (SEV 2012-0267), CTQ2015-67592-P, CTQ2015-70126-R, CTQ2015-68951-C3-1-R, MAT2015-71842-P, by the European Union ERC-AdG-2014-671093-SynCatMatch and by the Generalitat Valenciana PROMETEOII/2013/011 is acknowledged. Z. Li acknowledges China Scholarship Council (CSC) for a fellowship. J. Yu thanks the Major International Joint Research Project of China for financial support (Grant No. 21320102001).Li, Z.; Navarro Villalba, MT.; Martínez Triguero, LJ.; Yu, J.; Corma Canós, A. (2016). Synthesis of nano-SSZ-13 and its application in the reaction of methanol to olefins. Catalysis Science and Technology. 6(15):5856-5863. https://doi.org/10.1039/C6CY00433DS5856586361

Nanocrystalline SSZ-39 zeolite as an efficient catalyst for the methanol-to-olefin (MTO) process

[EN] The synthesis of nanosized SSZ-39 zeolite has been achieved using a high silica FAU zeolite as the Si and Al source and tetraethylphosphonium (TEP) cations as OSDAs. The obtained SSZ-39 material shows a remarkably high catalyst lifetime compared to conventional SSZ-13 and SSZ-39 materials.Financial support by the Spanish Government-MINECO through ‘‘Severo Ochoa’’ (SEV2012-0267), MAT2015-71261-R, and CTQ2015-68951-C3-1-R is acknowledged. The European Union is also acknowledged by the SYNCATMATCH project (Grant Agreement no. 671093). N. M. thanks MINECO for economical support through pre-doctoral fellowship (BES-2013-064347). J. Y. and A. C. thank the National Natural Science Foundation of China (21320102001) for supporting this work.Martín García, N.; Li, Z.; Martínez Triguero, LJ.; Yu, J.; Moliner Marin, M.; Corma Canós, A. (2016). Nanocrystalline SSZ-39 zeolite as an efficient catalyst for the methanol-to-olefin (MTO) process. Chemical Communications. 52(36):6072-6075. https://doi.org/10.1039/C5CC09719CS60726075523

The oxidation of trichloroethylene over different mixed oxides derived from hydrotalcites

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

Cu and Co modified beta zeolite catalysts for the trichloroethylene oxidation

[EN] In this work we have studied for the first time the catalytic activity for the oxidation of trichloroethylene (TCE) of Cu and Co beta zeolites. The results show that they are active and selective towards CO2, obtaining a better selectivity than that reached with conventional H-zeolites. The copper and cobalt zeolites have been prepared by different methods. It was found that their activity depends on the metal and on the preparation procedure. The most active catalyst was the Cu-BEA prepared by ion exchange (T-50% =310 degrees C and T-90% =360 degrees C). This catalyst has the highest ammonia adsorption capacity (as a measurement of the acidity) and it was the only tested material in which the Me2+ was completely reduced in a standard H-2-TPR experiment (indicative of its important redox properties). Thus, the enhanced activity of the Cu-exchanged zeolite was associated to the presence of strong acid sites in the zeolite and to the redox properties of the copper ion exchanged. The catalyst was stable at 300 degrees C for almost 70 h without any important deactivation. This was related to the oxidative properties of the copper that avoid the formation of coke on the strong acid sites of the zeolite. On the other hand, zeolites with the transition metal incorporated into the zeolite framework by hydrothermal synthesis showed lower catalytic activity, probably because the formation of small oxide particles with much less interaction with the silicate framework, that results in a lower redox activity of the transition metals. It has been shown that a proper combination of acidity, redox properties and metal-zeolite interaction is necessary in order to prepare an active and selective zeolite catalyst for the TCE oxidation.The authors wish to thank the Spanish Ministry of Economy and Competitiveness through the MAT-2012-38567-C02-01 and to the DGICYT through the project CTQ2012-37925-C03-1 for the financial support. N.B.R. acknowledges Catedra Cemex Sostenibilidad (UPV) for a fellowship.Blanch Raga, N.; Palomares Gimeno, AE.; Martínez Triguero, LJ.; Valencia Valencia, S. (2016). Cu and Co modified beta zeolite catalysts for the trichloroethylene oxidation. Applied Catalysis B: Environmental. 187:90-97. https://doi.org/10.1016/j.apcatb.2016.01.029S909718

Oxidative Degradation of Trichloroethylene over Fe2O3-doped Mayenite: Chlorine Poisoning Mitigation and Improved Catalytic Performance

[EN] Mayenite was recently successfully employed as an active catalyst for trichloroethylene (TCE) oxidation. It was effective in promoting the conversion of TCE in less harmful products (CO2 and HCl) with high activity and selectivity. However, there is a potential limitation to the use of mayenite in the industrial degradation of chlorinated compounds-its limited operating lifespan owing to chlorine poisoning of the catalyst. To overcome this problem, in this work, mayenite-based catalysts loaded with iron (Fe/mayenite) were prepared and tested for TCE oxidation in a gaseous phase. The catalysts were characterized using different physico-chemical techniques, including XRD, ICP, N-2-sorption (BET), H-2-TPR analysis, SEM-EDX, XPS FESEM-EDS, and Raman. Fe/mayenite was found to be more active and stable than the pure material for TCE oxidation, maintaining the same selectivity. This result was interpreted as the synergistic effect of the metal and the oxo-anionic species present in the mayenite framework, thus promoting TCE oxidation, while avoiding catalyst deactivation.This work was supported by the grants ORSA167988 and ORSA174250 funded by the University of Salerno. AEP and JLC thank the Spanish Ministry of Economy and Competitiveness through RTI2018-101784-B-I00 and SEV-2016-0683 for the financial support. J.L. Cerrillo wishes to thank the Spanish Ministry of Economy and Competitiveness for the Severo Ochoa PhD fellowship (SVP-2014-068600).Cucciniello, R.; Intiso, A.; Siciliano, T.; Palomares Gimeno, AE.; Martínez-Triguero, J.; Cerrillo, JL.; Proto, A.... (2019). Oxidative Degradation of Trichloroethylene over Fe2O3-doped Mayenite: Chlorine Poisoning Mitigation and Improved Catalytic Performance. Catalysts. 9(9):1-13. https://doi.org/10.3390/catal9090747S11399Rossi, F., Cucciniello, R., Intiso, A., Proto, A., Motta, O., & Marchettini, N. (2015). Determination of the trichloroethylene diffusion coefficient in water. AIChE Journal, 61(10), 3511-3515. doi:10.1002/aic.14861Ko, J. H., Musson, S., & Townsend, T. (2010). Destruction of trichloroethylene during hydration of calcium oxide. Journal of Hazardous Materials, 174(1-3), 876-879. doi:10.1016/j.jhazmat.2009.09.043Ge, J., Huang, S., Han, I., & Jaffé, P. R. (2019). Degradation of tetra- and trichloroethylene under iron reducing conditions by Acidimicrobiaceae sp. A6. Environmental Pollution, 247, 248-255. doi:10.1016/j.envpol.2019.01.066Moccia, E., Intiso, A., Cicatelli, A., Proto, A., Guarino, F., Iannece, P., … Rossi, F. (2016). Use of Zea mays L. in phytoremediation of trichloroethylene. Environmental Science and Pollution Research, 24(12), 11053-11060. doi:10.1007/s11356-016-7570-8Meyer, C. I., Borgna, A., Monzón, A., & Garetto, T. F. (2011). Kinetic study of trichloroethylene combustion on exchanged zeolites catalysts. Journal of Hazardous Materials, 190(1-3), 903-908. doi:10.1016/j.jhazmat.2011.04.007Cucciniello, R., Proto, A., Rossi, F., Marchettini, N., & Motta, O. (2015). An improved method for BTEX extraction from charcoal. Analytical Methods, 7(11), 4811-4815. doi:10.1039/c5ay00828jIntiso, A., Miele, Y., Marchettini, N., Proto, A., Sánchez-Domínguez, M., & Rossi, F. (2018). Enhanced solubility of trichloroethylene (TCE) by a poly-oxyethylene alcohol as green surfactant. Environmental Technology & Innovation, 12, 72-79. doi:10.1016/j.eti.2018.08.001Garza‐Arévalo, J. I., Intiso, A., Proto, A., Rossi, F., & Sanchez‐Dominguez, M. (2019). Trichloroethylene solubilization using a series of commercial biodegradable ethoxylated fatty alcohol surfactants. Journal of Chemical Technology & Biotechnology, 94(11), 3523-3529. doi:10.1002/jctb.5965Aranzabal, A., Pereda-Ayo, B., González-Marcos, M., González-Marcos, J., López-Fonseca, R., & González-Velasco, J. (2014). State of the art in catalytic oxidation of chlorinated volatile organic compounds. Chemical Papers, 68(9). doi:10.2478/s11696-013-0505-7Li, D., Li, C., & Suzuki, K. (2013). Catalytic oxidation of VOCs over Al- and Fe-pillared montmorillonite. Applied Clay Science, 77-78, 56-60. doi:10.1016/j.clay.2013.02.027Tian, W., Fan, X., Yang, H., & Zhang, X. (2010). Preparation of MnOx/TiO2 composites and their properties for catalytic oxidation of chlorobenzene. Journal of Hazardous Materials, 177(1-3), 887-891. doi:10.1016/j.jhazmat.2009.12.116Blanch-Raga, N., Palomares, A. E., Martínez-Triguero, J., Puche, M., Fetter, G., & Bosch, P. (2014). The oxidation of trichloroethylene over different mixed oxides derived from hydrotalcites. Applied Catalysis B: Environmental, 160-161, 129-134. doi:10.1016/j.apcatb.2014.05.014Taralunga, M., Mijoin, J., & Magnoux, P. (2006). Catalytic destruction of 1,2-dichlorobenzene over zeolites. Catalysis Communications, 7(3), 115-121. doi:10.1016/j.catcom.2005.09.006Romero-Sáez, M., Divakar, D., Aranzabal, A., González-Velasco, J. R., & González-Marcos, J. A. (2016). Catalytic oxidation of trichloroethylene over Fe-ZSM-5: Influence of the preparation method on the iron species and the catalytic behavior. Applied Catalysis B: Environmental, 180, 210-218. doi:10.1016/j.apcatb.2015.06.027Blanch-Raga, N., Palomares, A. E., Martínez-Triguero, J., & Valencia, S. (2016). Cu and Co modified beta zeolite catalysts for the trichloroethylene oxidation. Applied Catalysis B: Environmental, 187, 90-97. doi:10.1016/j.apcatb.2016.01.029Cucciniello, R., Proto, A., Rossi, F., & Motta, O. (2013). Mayenite based supports for atmospheric NOx sampling. Atmospheric Environment, 79, 666-671. doi:10.1016/j.atmosenv.2013.07.065Cucciniello, R., Intiso, A., Castiglione, S., Genga, A., Proto, A., & Rossi, F. (2017). Total oxidation of trichloroethylene over mayenite (Ca12Al14O33) catalyst. Applied Catalysis B: Environmental, 204, 167-172. doi:10.1016/j.apcatb.2016.11.035Intiso, A., Martinez-Triguero, J., Cucciniello, R., Proto, A., Palomares, A. E., & Rossi, F. (2019). A Novel Synthetic Route to Prepare High Surface Area Mayenite Catalyst for TCE Oxidation. Catalysts, 9(1), 27. doi:10.3390/catal9010027Intiso, A., Martinez-Triguero, J., Cucciniello, R., Rossi, F., & Palomares, A. E. (2019). Influence of the synthesis method on the catalytic activity of mayenite for the oxidation of gas-phase trichloroethylene. Scientific Reports, 9(1). doi:10.1038/s41598-018-36708-2Proto, A., Cucciniello, R., Rossi, F., & Motta, O. (2013). Stable carbon isotope ratio in atmospheric CO2 collected by new diffusive devices. Environmental Science and Pollution Research, 21(4), 3182-3186. doi:10.1007/s11356-013-2369-3Eufinger, J.-P., Schmidt, A., Lerch, M., & Janek, J. (2015). Novel anion conductors – conductivity, thermodynamic stability and hydration of anion-substituted mayenite-type cage compounds C12A7:X (X = O, OH, Cl, F, CN, S, N). Physical Chemistry Chemical Physics, 17(10), 6844-6857. doi:10.1039/c4cp05442cSchmidt, A., Lerch, M., Eufinger, J.-P., Janek, J., Tranca, I., Islam, M. M., … Hölzel, M. (2014). Chlorine ion mobility in Cl-mayenite (Ca12Al14O32Cl2): An investigation combining high-temperature neutron powder diffraction, impedance spectroscopy and quantum-chemical calculations. Solid State Ionics, 254, 48-58. doi:10.1016/j.ssi.2013.10.042Teusner, M., De Souza, R. A., Krause, H., Ebbinghaus, S. G., Belghoul, B., & Martin, M. (2015). Oxygen Diffusion in Mayenite. The Journal of Physical Chemistry C, 119(18), 9721-9727. doi:10.1021/jp512863uRuszak, M., Inger, M., Witkowski, S., Wilk, M., Kotarba, A., & Sojka, Z. (2008). Selective N2O Removal from the Process Gas of Nitric Acid Plants Over Ceramic 12CaO · 7Al2O3 Catalyst. 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Mesopore-modified mordenites as catalysts for catalytic pyrolysis of biomass and cracking of vacuum gasoil processes

[EN] Mesopore-modified mordenite zeolitic materials with different Si/Al ratios have been repared and tested in the biomass pyrolysis and catalytic cracking of vacuum gasoil. Alkaline treatment was carried out to generate mesoporosity. Severity of alkaline treatment was found to be of paramount importance to tune the generated mesoporosity, while it significantly affected the crystallinity of treated mordenites. It was moreover observed that the alkaline treatment selectively extracted Si decreasing the Si/Al ratio of treated samples. Catalytic activity of parent and alkaline treated mordenites was studied in the pyrolysis of biomass. All zeolitic based materials produced less amounts of bio-oil but of better quality (lowering the oxygen content from ∼40% to as much as 21%) as compared to the non-catalytic pyrolysis experiments. On the other hand, it was found that the combination of mesopore formation and high surface area after alkaline treatment of the mordenite with a high Si/Al ratio resulted in the enhancement of its catalytic activity, despite the reduction of its acidity. The increment of the decarboxylation and dehydration reactions, combined with a reduction of carbon deposition on the catalyst, resulted in a remarkable decrease in the oxygen content in the organic fraction and therefore, resulted in a superior quality liquid product. Alkaline treated mordenites were additionally acid treated targeting dealumination and removal of the extra framework debris, thus generating mesopore-modified mordenite samples with stronger acid sites and higher total acidity, as candidate catalysts for catalytic cracking of vacuum gasoil. Desilicated and especially desilicated and dealuminated mordenites exhibited the highest activity and selectivity towards LCO with the best olefinicity in gases and higher bottoms conversion. Therefore, an optimized desilicated dealuminated mordenite additive could be an interesting candidate as a component of the FCC catalyst for a high LCO yield.The financial support of this work by the ACENET COMMON INITIATIVE HECABIO: "HEterogeneous CAtalysis for the Conversion of Solid BIOmass into Renewable Fuels and Chemicals" Project ACE.07.026 is gratefully acknowledged.Stefanidis, S.; Kalogiannis, K.; Iliopoulou, EF.; Lappas, AA.; Martínez Triguero, LJ.; Navarro Ruiz, MT.; Chica, A.... (2013). Mesopore-modified mordenites as catalysts for catalytic pyrolysis of biomass and cracking of vacuum gasoil processes. Green Chemistry. 15(6):1647-1658. doi:10.1039/c3gc40161hS1647165815