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[ES] En la presente invención, se describe un nuevo procedimiento de síntesis del material intercrecido CHA/AEI en su forma zeolítica utilizando un único agente director de estructura orgánico (ADEO), mucho más sencillo que las mezclas descritas hasta el momento, y en ausencia de aniones fluoruro en el medio de síntesis. En la presente invención también se describe el material obtenido con dicho procedimiento y su uso como catalizador en diversos procesos catalíticos, como metanol a olefinas, y la reducción catalítica selectiva (RCS) de distintos óxidos de nitrógeno (NOx) en emisiones gaseosas., [EN] The present invention relates to a new method for synthesising CHA/AEI intergrown material in its zeolitic form using a single organic structure-directing agent (OSDA), which is much simpler than previously described mixtures, and in which the synthesis medium is free of fluoride anions. The present invention also relates to the material obtained with said method and the use thereof as a catalyst in various catalytic processes, such as the methanol-to-olefin process, and the selective catalytic reduction (SCR) of different nitrogen oxides (NOx) in gaseous emissions., [FR] La présente invention porte sur un nouveau procédé de synthèse du matériau entrecroisé CHA/AEI dans sa forme zéolithique au moyen d'un agent directeur unique de structure organique (ADEO), beaucoup plus simple que les mélanges décrits jusqu'à ce jour, et en l'absence d'anions fluorure dans le milieu de synthèse. L'invention porte également sur le matériau obtenu au moyen dudit procédé et sur son utilisation comme cstalyseur dans divers processus catalytiques, comme la conversion de méthanol en oléfines et la réduction catalytique sélective (RCS) de différents oxydes d'azote (NOx) en émissions gazeuses.

A novel ab initio methodology based on high-throughput simulations has permitted designing unique biselective organic structure-directing agents (OSDAs) that allow the efficient synthesis of CHA/AEI zeolite intergrowth materials with controlled phase compositions. Distinctive local crystallographic ordering of the CHA/AEI intergrowths was revealed at the nanoscale level using integrated differential phase contrast scanning transmission electron microscopy (iDPC STEM). These novel CHA/AEI materials have been tested for the selective catalytic reduction (SCR) of NOx, presenting an outstanding catalytic performance and hydrothermal stability, even surpassing the performance of the well-established commercial CHA-type catalyst. This methodology opens the possibility for synthetizing new zeolite intergrowths with more complex structures and unique catalytic properties.

Organic structure directing agents (OSDAs) play a crucial role in the synthesis of micro-and mesoporous materials especially in the case of zeolites. Despite the wide use of OSDAs, their interaction with zeolite frameworks is poorly understood, with researchers relying on synthesis heuristics or computationally expensive techniques to predict whether an organic molecule can act as an OSDA for a certain zeolite. In this paper, we undertake a data-driven approach to unearth generalized OSDA-zeolite relationships using a comprehensive database comprising of 5,663 synthesis routes for porous materials. To generate this comprehensive database, we use natural language processing and text mining techniques to extract OSDAs, zeolite phases, and gel chemistry from the scientific literature published between 1966 and 2020. Through structural featurization of the OSDAs using weighted holistic invariant molecular (WHIM) descriptors, we relate OSDAs described in the literature to different types of cage-based, small-pore zeolites. Lastly, we adapt a generative neural network capable of suggesting new molecules as potential OSDAs for a given zeolite structure and gel chemistry. We apply this model to CHA and SFW zeolites generating several alternative OSDA candidates to those currently used in practice. These molecules are further vetted with molecular mechanics simulations to show the model generates physically meaningful predictions. Our model can automatically explore the OSDA space, reducing the amount of simulation or experimentation needed to find new OSDA candidates.

Zeolites are versatile catalysts and molecular sieves with large topological diversity, but managing phase competition in zeolite synthesis is an empirical, labor-intensive task. In this work, we controlled phase selectivity in templated zeolite synthesis from first principles by combining high-throughput atomistic simulations, literature mining, human-computer interaction, synthesis, and characterization. Proposed binding metrics distilled from more than 586,000 zeolite-molecule simulations reproduced the extracted literature and rationalized framework competition in the design of organic structure-directing agents. Energetic, geometric, and electrostatic descriptors of template molecules were found to regulate synthetic accessibility windows and aluminum distributions in pure-phase zeolites. Furthermore, these parameters allowed us to realize an intergrowth zeolite through a single bi-selective template. The computation-first approach enables control of both zeolite synthesis and structure composition using a priori theoretical descriptors.

By combining kinetics and theoretical calculations, we show here the benefits of going beyond the concept of static localized and defined active sites on solid catalysts, into a system that globally and dynamically considers the active site located in an environment that involves a scaffold structure particularly suited for a target reaction. We demonstrate that such a system is able to direct the reaction through a preferred mechanism when two of them are competing. This is illustrated here for an industrially relevant reaction, the diethylbenzene-benzene transalkylation. The zeolite catalyst (ITQ-27) optimizes location, density, and environment of acid sites to drive the reaction through the preselected and preferred diaryl-mediated mechanism, instead of the alkyl transfer pathway. This is achieved by minimizing the activation energy of the selected pathway through weak interactions, much in the way that it occurs in enzymatic catalysts. We show that ITQ-27 outperforms previously reported zeolites for the DEB-Bz transalkylation and, more specifically, industrially relevant zeolites such as faujasite, beta, and mordenite.

The light olefin product distribution of the methanol-to-olefin (MTO) reaction catalyzed by acid zeolites and zeotypes depends on the nature of the entrapped hydrocarbon pool species that act as co-catalysts. The preferential stabilization by confinement effects of the cationic intermediates involved in the side-chain or paring pathways of the aromatics-based cycle of the MTO mechanism in small-pore cage-based zeolites is determined by the topology of the cavity, and can be quantitatively described through the E parameter obtained from DFT calculations. In this work we extend the study of the E parameter to a wide range of structures (ERI, LEV, AEI, CHA, DDR, AFX, RTH, ITE, SAV, UFI, RHO, KFI, and LTA) and discuss its applicability in small cages with steric constraints to host bulky intermediates, in zeolites with a tight fitting between the cavity and the hosted cations, and in large cages where confinement effects are lost in part and competitive processes occur.

En la presente invención, se describe un nuevo procedimiento de síntesis del material intercrecido CHA/AEI en su forma zeolítica utilizando un único agente director de estructura orgánico (ADEO), mucho más sencillo que las mezclas descritas hasta el momento, y en ausencia de aniones fluoruro en el medio de síntesis. En la presente invención también se describe el material obtenido con dicho procedimiento y su uso como catalizador en diversos procesos catalíticos, como metanol a olefinas, y la reducción catalítica selectiva (RCS) de distintos óxidos de nitrógeno (NOx) en emisiones gaseosas

The present invention relates to a new process for synthesising a crystalline material comprising structure Beta zeolite in nanocrystalline form, and which can comprise at least the following steps: (i) preparing a mixture comprising at least one source of water, at least one source of a tetravalent element Y, at least one source of a trivalent element X, at least one source of an alkali cation or alkaline earth metal cation (A), and at least one organic molecule selected from a monocyclic quaternary ammonium R1R2CycloN+, and a quaternary ammonium substituted with a cycloalkyl group R3R4R5R6N+. The molar composition of the mixture is: n X2O3:YO2:a A:m OSDA1:z H2O; ii) crystallising the mixture; and iii) recovering the crystalline material

Procedimiento de síntesis de un material con estructura zeolítica MWW en su forma nanocristalina, que comprende los siguientes pasos: i) Preparación de una mezcla que comprenda una fuente de agua, al menos una fuente de un elemento tetravalente Y, al menos una fuente de un elemento trivalente X, al menos una fuente de un catión alcalino o alcalinotérreo (A), y al menos dos moléculas orgánicas (ADE01 y ADE02), donde ADE01 es un amonio cuaternario monocíclico en que uno de los sustituyeles es una cadena alquílica de 3-6 átomos de carbono, y ADE02 está seleccionado entre cualquier amina o amonio capaz de dirigir la formación de MWW. ¡i) Cristalización de la mezcla obtenida en i) en un reactor iü) Recuperación del material cristalino obtenido en ¡i). [ES], The invention relates to a method for synthesising a material with an MWW zeolite structure in its nanocrystalline form, which comprises the following steps: i) preparing a mixture comprising a water source, at least one source of a tetravalent element Y, at least one source of a trivalent element X, at least one source of an alkaline cation or alkaline earth metal cation (A), and at least two organic molecules (ADE01 and ADE02), wherein ADE01 is a monocyclic quaternary ammonium in which one of the substituents is an alkyl chain of 3-6 carbon atoms, and ADE02 is selected from any amine or ammonium able to direct the formation of MWW; ii) crystallising the mixture obtained in step i) in a reactor; and iii) recovering the crystalline material obtained in step ii). [EN]

Procedimiento de síntesis del material MWW en su forma nanocristalina y su uso en aplicaciones catalíticas. Procedimiento de síntesis de un material con estructura zeolítica MVWV en su forma nanocristalina, que comprende los siguientes pasos: i) Preparación de una mezcla que comprenda una fuente de agua, al menos una fuente de un elemento tetravalente Y, al menos una fuente de un elemento trivalente X, al menos una fuente de un catión alcalino o alcalinotérreo (A), y al menos dos moléculas orgánicas (ADEO1 y ADEO2), donde ADEO1 es un amonio cuaternario monocíclico en que uno de los sustituyentes es una cadena alquílica de 3-6 átomos de carbono, y ADEO2 está seleccionado entre cualquier amina o amonio capaz de dirigir la formación de MWW. ii) Cristalización de la mezcla obtenida en i) en un reactor. iii) Recuperación del material cristalino obtenido en ii).

The selective incorporation of isolated framework Lewis acid sites at specific crystallographic positions in high-silica zeolites was achieved by applying a rationalized post-synthetic grafting methodology. The removal of framework Ge atoms from a Ge-BEC zeolite with low concentrations of Ge in the framework (Si/Ge ∼ 150) followed by grafting allows the synthesis of Sn-BEC zeolites with Sn atoms positionally biased into the double-4-ring (D4R) crystallographic positions of the BEC framework. Spectroscopic characterization using solid-state nuclear magnetic resonance (NMR) coupled with theoretical calculations revealed that Sn atoms preferentially form open Sn sites in the D4R of Sn-BEC. This observation was supported by IR spectra of adsorbed deuterated acetonitrile (CD3CN), a known titrant of Sn sites in zeolites. The catalytic implications of selective incorporation of open Sn sites in Sn-BEC were probed using the Meerwein-Ponndorf-Verley-Oppenauer (MPVO) reaction. Although the MPVO turnover rates normalized by the total number of open Sn sites were comparable on Sn-BEC and a conventional Sn-Beta catalyst synthesized in fluoride media (Sn-Beta(F)), Sn-BEC demonstrated higher per gram reaction rates because of its larger fraction of open sites compared to Sn-Beta(F). These results highlight the advantage of placing active sites in targeted locations within a zeolite structure. The methodology presented here to selectively place catalytic active sites via sacrificial heteroatoms, such as Ge, can be generalized for the design of many other tetrahedrally-coordinated metal-containing zeolites. This journal is

Taking into account that the transformation of biomass-derived 2,5-dimethylfuran (DMF) to p-xylene involves Diels-Alder (DA) cycloaddition as the limiting step, the use of an ITQ-2 zeolite obtained by direct synthesis (DS-ITQ-2) as a catalyst for this reaction is proposed based on the fact that the organic molecule employed for its synthesis mimics the size and shape of the DA oxanorbornene cycloadduct intermediate. Periodic Density Functional Theory (DFT) calculations reveal a better stabilization of the oxanorbornene intermediate within the external hemicavities or "cups"of the DS-ITQ-2 zeolite (MWW-framework) than in other zeolites employed for this reaction, such as FAU and Beta. Interestingly, experimental results also show improved catalytic conversion values for the DS-ITQ-2 zeolite compared to FAU and Beta, in good agreement with the stabilization energies calculated by DFT. The "ab initio"catalyst design presented here to enhance the catalytic performance for the transformation of biomass-derived products is a valuable example that could be employed for the rationalization of other chemical processes catalyzed by zeolites.

By using a Diels-Alder (DA) reaction as a base case, we show that a pure silica zeolite acting as an entropy-trapping scaffold can be synthesized with an organic structure directing agent (OSDA) analogue of the transition state (TS) of the DA reaction. A cavity stabilization of the TS is observed with the corresponding decrease in the activation energy of the reaction. A lower enthalpy of activation and a larger decrease in entropy are obtained with the zeolite synthesized with the analogue of the DA TS when compared with other zeolitic structures. Those differences are maintained, while catalytic activity is increased, when active sites are introduced in the zeolite. The catalytic zeolitic system synthesized with the OSDA analogue of the TS shows conceptual similarities with >de novo design> of an artificial enzyme to perform DA reactions, in where a suitable scaffold of existing proteins is chosen, and computationally designed active sites able to catalyze the cycloaddition reaction are introduced.

Síntesis de la zeolita cha en su forma nanocristalina, procedimiento de síntesis y su uso en aplicaciones catalíticas. La presente invención se refiere a un proceso de síntesis del silicoaluminato con estructura zeolítica CHA en su forma nanocristalina, que puede comprender, al menos, los siguientes pasos: i) Preparación de una mezcla que contenga, al menos, agua, una zeolita con la estructura cristalina FAU, como puede ser la zeolita Y, como única fuente de silicio y aluminio, y una molécula orgánica capaz de dirigir la formación de la zeolita CHA (ADEO1) donde ADEO1 puede ser cualquier molécula orgánica capaz de dirigir la cristalización de la zeolita CHA, y donde la composición molar de la mezcla de síntesis puede ser la siguiente: SiO2: a Al2O3:b ADEO1 : c H2O; ii) Cristalización de la mezcla obtenida en (i) en un reactor; y iii) Recuperación del material cristalino obtenido en (ii).

[EN] The present invention relates to a process for the synthesis of silicoaluminate with zeolite structure CHA in the nanocrystalline form thereof, which can comprise at least the following steps: i) preparing a mixture that contains at least water, a zeolite with FAU crystalline structure, such as the zeolite Y, as single source of silicon and aluminium, and an organic molecule capable of directing the formation of the zeolite CHA (ADE01), wherein ADE01 can be any organic molecule capable of directing the crystallisation of the zeolite CHA, and wherein the molar composition of the synthesis mixture can be as follows: SiO2: a AI2O3: b ADE01: c H2O; ii) crystallising the mixture obtained in (i) in a reactor; and iii) recovering the crystalline material obtained in (ii), [ES] La presente invención se refiere a un proceso de síntesis del siiicoaluminato con estructura zeolítica CHA en su forma nanocristaüna, que puede comprender, al menos, los siguientes pasos: i) Preparación de una mezcla que contenga, al menos, agua, una zeolita con la estructura cristalina FAU, como puede ser la zeolita Y, como única fuente de silicio y aluminio, y una molécula orgánica capaz de dirigir la formación de la zeolita CHA (ADE01 ) donde ADE01 puede ser cualquier molécula orgánica capaz de dirigir la cristalización de la zeolita CHA, y donde la composición molar de la mezcla de síntesis puede ser la siguiente: SiO2 : a AI2O3 : b ADE01 : c H2O; ii) Cristalización de la mezcla obtenida en (i) en un reactor; y iii) Recuperación del material cristalino obtenido en (ii), [FR] La présente invention concerne un procédé de synthèse du silicoaluminate à structure zéolithique CHA sous sa forme nanocristalline, pouvant comprendre au moins les étapes suivantes : i) préparation d'un mélange contenant au moins de l'eau, une zéolithe à structure cristalline FAU, telle que la zéolithe Y, en tant que source unique de silicium et d'aluminium, et une molécule organique pouvant diriger la formation de la zéolithe CHA (ADE01), ADE01 pouvant être une molécule organique quelconque pouvant diriger la cristallisation de la zéolithe CHA, la composition molaire du mélange de synthèse pouvant être la suivante : SiO2 : a AI2O3 : b ADE01 : c H2O ; ii) cristallisation du mélange obtenu dans l'étape i) dans un réacteur ; et iii) récupération de la matière cristalline obtenue dans l'étape ii)

The catalysts used in the methanol-to-olefins (MTO) reaction are considered dual systems comprising an inorganic zeolite framework and organic compounds hosted inside that act as cocatalysts. The influence of zeolite cavity architecture on the preferential stabilization of cationic intermediates involved in the paring and side-chain routes of the hydrocarbon pool mechanism is analyzed by means of density functional theory (DFT) calculations, catalyst testing, and 13C NMR spectroscopy for some small-pore cage-based zeolites. A correlation between the degree of methylation of the entrapped methylbenzenium (MB+) cations and the selectivity to ethene and propene is found experimentally and explained in terms of the electronic distribution of the first intermediate of the paring route. A deep understanding of the reaction mechanism and of the specific host–guest interactions taking place inside zeolite catalysts allows establishing a quantitative parameter that is indicative for the contribution of the paring route and therefore the C3=/C2= ratio in the MTO reaction.

The present invention relates to a new process for synthesising a crystalline material comprising the structure Beta zeolite in nanocrystalline form, and which can comprise at least the following steps: (i) preparing a mixture comprising at least one source of water, at least one source of a tetravalent element Y, at least one source of a trivalent element X, at least one source of an alkali cation or alkaline earth metal cation (A), and at least one organic molecule selected from a monocyclic quaternary ammonium R1R2CycloN+, and a quaternary ammonium substituted with a cycloalkyl group R3R4R5R6N+, the molar composition of the mixture being n X2O3 : YO2 : a A : m ADEO1 : z H2O; (ii) crystallising the mixture; and (iii) recovering the crystalline material. [EN], La presente invención se refiere a un nuevo proceso de síntesis de un material cristalino que presenta la estructura zeoiítica Beta en su forma nanocristalina, y que puede comprender, al menos, los siguientes pasos: i) Preparación de una mezcla que comprenda al menos una fuente de agua, ai menos una fuente de un elemento tetravalente Y, al menos una fuente de un elemento trivalente X, ai menos una fuente de un catión alcalino o alcalinotérreo (A), y al menos una molécula orgánica seleccionada entre un amonio cuaternario monocíclico R1R2CycloN+, y un amonio cuaternario sustituido con un grupo cicloalquílico R3R4R5R6N+. La composición molar de la mezcla es: n X2O3 : YO2 : a A : m ADEO1 : z H2O; ii) Cristalización de dicha mezcla: y iii) Recuperación del material cristalino. [ES]

Síntesis de la zeolita MFI en su forma nanocristalina, procedimiento de síntesis y su uso en aplicaciones catalíticas. La presente invención se refiere a un nuevo proceso de síntesis de un material cristalino que presenta la estructura zeolítica MFI en su forma nanocristalina, y que puede comprender, al menos, los siguientes pasos: i) Preparación de una mezcla que comprenda al menos una fuente de agua, al menos una fuente de un elemento tetravalente Y, al menos una fuente de un elemento trivalente X, al menos una fuente de un catión alcalino o alcalinotérreo (A), y al menos una molécula orgánica (ADEO1), donde ADEO1 es preferentemente un amonio cuaternario monocíclico con la estructura R1R2CycloN+. La composición molar de la mezcla es: n X2O3 : YO2 : a A : m ADEO1 : z H2O; ii) Cristalización de esta mezcla en un reactor; y iii) Recuperación del material cristalino obtenido.

From theoretical calculations and a rational synthesis methodology, it has been possible to prepare nanocrystalline (60–80 nm) chabazite with an optimized framework Al distribution that has a positive impact on its catalytic properties. This is exemplified for the methanol-to-olefin (MTO) process. The nanosized material with the predicted Al distribution maximizes the formation of the required MTO hydrocarbon pool intermediates, while better precluding excessive diffusion pathways that favor the rapid catalyst deactivation by coke formation.

Catalysis with enzymes and zeolites have in common the presence of well-defined single active sites and pockets/cavities where the reaction transition states can be stabilized by longer-range interactions. We show here that for a complex reaction, such as the conversion of methanol-to-olefins (MTO), it is possible to synthesize reaction-adapted zeolites by using mimics of the key molecular species involved in the MTO mechanism. Effort has focused on the intermediates of the paring mechanism because the paring is less favoured energetically than the side-chain route. All the organic structure-directing agents based on intermediate mimics crystallize cage-based small-pore zeolitic materials, all of them capable of performing the MTO reaction. Among the zeolites obtained, RTH favours the whole reaction steps following the paring route and gives the highest propylene/ethylene ratio compared to traditional CHA-related zeolites (3.07 and 0.86, respectively).

Non surfactant cyclic alkylammonium can selectively decrease the rate of crystal growth along the x¿y crystal axes during the synthesis of MWW zeolite. This results in an ~60 nm nanocrystalline zeolite that shows remarkable catalytic properties for the production of cumene.

[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).

[EN] Unlike homogeneous catalysts that are often designed for particular reactions, zeolites are heterogeneous catalysts that are explored and optimized in a heuristic fashion. We present a methodol. for synthesizing active and selective zeolites by using org. structure-¿directing agents that mimic the transition state (TS) of preestablished reactions to be catalyzed. In these zeolites, the pores and cavities could be generated approaching a mol.-¿recognition pattern. For disproportionation of toluene and isomerization of ethylbenzene into xylenes, the TSs are larger than the reaction products. Zeolite ITQ-¿27 showed high disproportionation activity, and ITQ-¿64 showed high selectivity for the desired para and ortho isomers. For the case of a product and TS of similar size, we synthesized a catalyst, MIT-¿1, for the isomerization of endo-¿dicyclopentane into adamantane.

Unlike homogeneous catalysts that are often designed for particular reactions, zeolites are heterogeneous catalysts that are explored and optimized in a heuristic fashion. We present a methodology for synthesizing active and selective zeolites by using organic structure-directing agents that mimic the transition state (TS) of preestablished reactions to be catalyzed. In these zeolites, the pores and cavities could be generated approaching a molecular-recognition pattern. For disproportionation of toluene and isomerization of ethylbenzene into xylenes, the TSs are larger than the reaction products. Zeolite ITQ-27 showed high disproportionation activity, and ITQ-64 showed high selectivity for the desired para and ortho isomers. For the case of a product and TS of similar size, we synthesized a catalyst, MIT-1, for the isomerization of endo-dicyclopentane into adamantane.

[EN] The synthesis of the ZSM-5 and beta zeolites in their nanosized form has been achieved by using simple alkyl-substituted mono-cationic cyclic ammonium cations as OSDA molecules. The particular combination of a cyclic fragment and a short linear alkyl-chain group (preferentially C4) within the monocationic OSDA molecules allows directing the crystallization of nanosized zeolites with excellent solid yields (above 90%). Interestingly, the formation of the nanosized ZSM-5 and beta zeolites mostly depends on the size and nature of the cyclic fragment of the OSDA molecule, resulting in all cases in nanocrystalline solids with homogeneous distributions of particle sizes (similar to 10-25 nm) and controlled Si/Al molar ratios (similar to 15-30). The achieved nanosized ZSM-5 and beta zeolites have been extensively characterized by different techniques to study their physico-chemical properties, such as chemical composition, pore accessibility or Bronsted acidity, among others. Moreover, the catalytic properties of the nanosized ZSM-5 and beta zeolites have been evaluated for different chemical reactions, including methanol-to-olefins (MTO) in the case of ZSM-5, and alkylation of benzene with propylene to obtain cumene and oligomerization of light olefins to liquid fuels in the case of beta, observing in all cases improved catalytic activity and product selectivity towards target products when compared to related catalysts.

It has been possible to efficiently synthesize high-silica ERI and AFX zeolites with nano-sized primary crystallites (30–200 nm). This was achieved by using a dicationic and rigid organic structure directing agent (OSDA) that fits within the large cavities of these zeolites, and the use of FAU zeolites as initial Si- and Al-sources. Cu- and Fe-based ERI and AFX materials were prepared following both post-synthetic cation exchange and direct synthesis methodologies, showing good activity for the selective catalytic reduction (SCR) of nitrogen oxide using ammonia. Accelerated hydrothermal ageing of the zeolites at high temperature (i.e. 750 °C) shows the necessity of removing the alkali cations remaining in the zeolites to obtain stable materials. Furthermore, the catalytic performance of the prepared Cu- and Fe-containing AFX catalysts, both before and after ageing treatment, approaches the catalytic activity of Cu- and Fe-CHA.

The synthesis of the ZSM-5 and beta zeolites in their nanosized form has been achieved by using simple alkyl-substituted mono-cationic cyclic ammonium cations as OSDA molecules. The particular combination of a cyclic fragment and a short linear alkyl-chain group (preferentially C) within the monocationic OSDA molecules allows directing the crystallization of nanosized zeolites with excellent solid yields (above 90%). Interestingly, the formation of the nanosized ZSM-5 and beta zeolites mostly depends on the size and nature of the cyclic fragment of the OSDA molecule, resulting in all cases in nanocrystalline solids with homogeneous distributions of particle sizes (∼10-25 nm) and controlled Si/Al molar ratios (∼15-30). The achieved nanosized ZSM-5 and beta zeolites have been extensively characterized by different techniques to study their physico-chemical properties, such as chemical composition, pore accessibility or Brønsted acidity, among others. Moreover, the catalytic properties of the nanosized ZSM-5 and beta zeolites have been evaluated for different chemical reactions, including methanol-to-olefins (MTO) in the case of ZSM-5, and alkylation of benzene with propylene to obtain cumene and oligomerization of light olefins to liquid fuels in the case of beta, observing in all cases improved catalytic activity and product selectivity towards target products when compared to related catalysts.

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 Brønsted 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 Brønsted 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.

[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.

The political struggles against the environmental, health, social, and economic impacts of neo-developmentalism and neo-extractivism in Latin America have been theoretically fertile. From the diversity of perspectives, we recover the contributions of a sociology of public problems for the struggles for Environmental Justice, basically because it promotes the practice of research as a reflexive and democratic form of cooperation between those directly environmentally affected and all those subject to a structure of environmental injustice. First, we present the epistemological, ethical and political dimension, defined by the active formation of a public. Secondly, we focus on the conceptual, strategic and institutional creativity of the public, with examples of the problems caused by the environmental and health impacts of the massive use of agrotoxics in gmo agriculture. Finally, we establish a bridge between the contributions of a sociology of public problems and Environmental Justice, the latter considered as a field of thought and action with competence in environmentalist discourses, meaning that the concept of justice is not reduced to state administration. Instead it refers to the diversity of practices in the public sphere, claiming and criticizing the unequal distribution of environmental risk and harm. At the same time, these practices creatively promote institutional reforms and transformations toward the full enforcement of rights and guarantees to life, health and the environment. A sociology of public problems aims to provide an understanding of the struggle for rights and recognition of forms of life, social and environmental equity and the right to democratic participation and the broad exercise of self-determination in building a society with environmental justice., La fecundidad teórica-política de las luchas contra los impactos ambientales, sanitarios, sociales, económicos del denominado neodesarrollismo y neoextractivismo, en América Latina, se encuentra en momentos acuciantes. Entre la diversidad de perspectivas, recuperamos los aportes de una sociología de los problemas públicos para abordar las luchas por la justicia ambiental, básicamente porque la práctica de investigación se promueve como una forma de cooperación reflexiva y democrática entre los afectados ambientales y todos lossujetos inmersos en una estructura de injusticias ambientales. Considerando, principalmente, algunas contribuciones del pragmatismo y de la teoría crítica, daremos cuenta de los rasgos distintivos de una sociología de los problemas públicos. En primer lugar, presentaremos su dimensión epistemológica, ética y política, definida por la activa formación de lo público. Ensegundo lugar, haremos énfasis en la creatividad conceptual, estratégica e institucional de lo público, con ejemplos de situaciones problemáticas que devienen de los impactos ambientales y sanitarios del uso masivo de agrotóxicos en la siembra de un organismo genéticamente modificado (OGM). En tercer lugar, estableceremos un puente entre los aportes de una sociología de los problemas públicos y la justicia ambiental, considerada un campo de pensamiento y acción de la competencia de discursos ambientalistas, en el que el concepto de justicia no se reduce a su administración estatal, sino que remite a una diversidad de prácticas en el espacio público estatal y ciudadano. Estas prácticas denuncian y critican la desigual distribución del riesgo y del daño ambiental, a la vez que promueven creativamente reformas y transformaciones institucionales para la plena vigencia de los derechos y las garantías a la vida, la salud y el ambiente. Una sociología de los problemas públicos pretende así aportar a la comprensión de las luchas por los derechos y el reconocimiento de formas de vida, por l, A fecundidade teórico-política das lutas contra os impactos ambientais, sanitários, sociais, econômicos do denominado neodesenvolvimento e neoextrativismo, na América Latina, encontra-se em momentos prementes. Entre a diversidade de perspectivas, recuperamos as contribuições de uma sociologia dos problemas públicos para abordar as lutas pela justiça ambiental, já que a prática de pesquisa é promovida como uma forma de cooperação reflexiva e democrática entre os afetados ambientais e todos os sujeitos imersos numa estrutura de injustiças ambientais. Considerando, principalmente, algumas contribuições do pragmatismo e da teoria crítica, trataremos dos traços diferenciais de uma sociologia dos problemas públicos. Em primeiro lugar, apresentaremos sua dimensão epistemológica, ética e política, definida pela ativa formação do público. Em seguida, enfatizaremos a criatividade conceitual, estratégica e institucional do público, com exemplos de situações problemáticas que derivam dos impactos ambientais e sanitários do uso massivo de agrotóxicos na semeadura de um organismo geneticamente modificado (ogm). Em terceiro lugar, estabeleceremos uma ponte entre as contribuições de uma sociologia dos problemas públicos e a justiça ambiental, considerada um campo de pensamento e ação da competência de discursos ambientalistas, no qual o conceito de justiça não se reduz a sua administração estatal, mas sim remete a uma diversidade de práticas no espaço público estatal e cidadão. Essas práticas denunciam e criticam a distribuição desigual do risco e do dano ambiental ao mesmo tempo que promovem criativamente reformas e transformações institucionais para a plena vigência dos direitos e das garantias à vida, à saúde e ao ambiente. Uma sociologia dos problemas públicos pretende, portanto, contribuir para a compreensão das lutas pelos direitos e pelo reconhecimento de formas de vida, pela equidade socioambiental e pelo direito à participação democrática e ao amplo exercício da autodeterm

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 metalcontaining 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 Xray 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 Brønsted acidity, and allowing their use as efficient heterogeneous acid catalysts in industrially relevant reactions involving bulky organic molecules.