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[EN] Delaminated and pillared zeolites are an innovative family of molecular sieves which introduced a different concept inside the synthesis of active catalysts or inorganic supports. These types of materials exhibit an elevated accessibility due to their open structure, characterized by the high external surface area without imposed restrictions controlled by the pore sizes. These open zeolites are conformed by crystalline ordered (pillared zeolites) or disordered (delaminated zeolites) individual layers, exhibiting textural properties which are favorable to carry out catalytic processes in which it is necessary to employ catalysts with completely accessible active sites. The elevated external surface area of these zeolites is profitable to generate more specific organic-inorganic materials, acting in this case as stable inorganic matrixes. The preparation of this open type-zeolites family is based on the modification of, previously synthesized, zeolitic precursors which are preexpanded to obtain the final delaminated or pillared zeolites which exhibit very different physicochemical properties compared with the starting precursors. Along this paper, the most relevantMWW-type high accessible zeoliticmaterials will be considered. Their nature, characteristics, and reactivity will be shown in the function of the employed synthesis method for their preparation and the postsynthesis treatments carried out, tuning their properties. ; The author thanks the Spanish Government (Consolider Ingenio 2010-MULTICAT (CSD2009–00050) and MAT2011–29020-C02-01) for the financial support. ; Díaz Morales, UM. (2012). Layered Materials with Catalytic Applications: Pillared andDelaminated Zeolites from MWW Precursors. ISRN Chemical Engineering. 2012(ID 537164):1-35. https://doi.org/10.5402/2012/537164 ; S ; 1 ; 35 ; 2012 ; ID 537164

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Chemistry of Materials, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/cm070553+ ; [EN] Layered organic-inorganic hybrid materials were synthesized by pillaring with viologen and nitroaniline compounds which are intercalated between magadiite layers. The bridged silsesquioxanes, 4,4'-bis(trimethoxysilylpropyl)viologen and 4-nitro-N,N'-bis(3-trimethoxysilyl)propylaniline react with the surface silanol groups of the inorganic layers of silicate, bonding covalently with them. The preparation process was followed by DRX, and the pillarization was corroborated using chemical and thermogravimetrical analyses. The presence of viologen and nitroaniline organic linkers covalently bonded to inorganic layers was confirmed by C-13 and Si-29 NMR spectroscopy. UV-visible diffuse reflectance permitted to observe the high stabilization achieved by the intercalated organic fragments. Micro- and mesoporosity were also generated because of the existence of interlayer galleries conformed by homogenously distributed organic linkers into the interlayer space. The layered organic-inorganic hybrids exhibited a thermally stable network, and the organic spacers remained after elimination of the swelling agents by acid extraction. The resultant materials can be of interest as sensors and for nonlinear optics. ; Financial support by the Spanish Government (MAT-2006-14274-C02-01 and MAT2006-26599-E) and Universidad Polite´cnica de Valencia (PPI-06-05) is gratefully acknowledged. ; Díaz Morales, UM.; Cantin Sanz, A.; Corma Canós, A. (2007). Novel layered organic-inorganic hybrid materirals with bridged silsesquioxanes as Pillars. Chemistry of Materials. 19(15):3686-3693. https://doi.org/10.1021/cm070553+ ; S ; 3686 ; 3693 ; 19 ; 15

[EN] We studied the influence of the ethanol used as a washing solvent for obtaining swollen and pillared MWW topology zeolites with long-range ordering of lamellar structure. The diffractogram results showed that the increased number of washes increases the degree of order of the lamellar structure. Thermogravimetric results showed a considerable removal of the weakly interacting surfactant molecules after the third wash. The washes with ethanol did not remove the surfactant that strongly interacted with the MWW structure. The pillared material after the third wash showed a long-range ordering of the lamellar structure with the surface area of 728 m(2) g(-1), mesopore sizes of 2-4 nm and morphology characteristic of pillared MWW-type zeolites. ; Anderson Joel Schwanke is grateful the CAPES Foundation and PDSE program (process number 99999.004779/2014-02). Urbano Diaz acknowledges to the Spanish Government (MAT2014-52085-C2-1-P and MAT2017-82288-C2-1-P). ; Schwanke, AJ.; Díaz Morales, UM.; Corma Canós, A.; Pergher, S. (2019). The influence of ethanol-assisted washes to obtain swollen and pillared MWW-type zeolite with high degree ordering of lamellar structure. Microporous and Mesoporous Materials. 275:26-30. https://doi.org/10.1016/j.micromeso.2018.08.010 ; S ; 26 ; 30 ; 275 ; Corma, A. (1997). From Microporous to Mesoporous Molecular Sieve Materials and Their Use in Catalysis. Chemical Reviews, 97(6), 2373-2420. doi:10.1021/cr960406n ; IZA, International Zeolite Association, web page http://www.iza-structure.org/. ; Roth, W. J., Nachtigall, P., Morris, R. E., & Čejka, J. (2014). Two-Dimensional Zeolites: Current Status and Perspectives. Chemical Reviews, 114(9), 4807-4837. doi:10.1021/cr400600f ; Díaz, U., & Corma, A. (2014). Layered zeolitic materials: an approach to designing versatile functional solids. Dalton Transactions, 43(27), 10292. doi:10.1039/c3dt53181c ; Corma, A., Fornes, V., Pergher, S. B., Maesen, T. L. M., & Buglass, J. G. (1998). Delaminated zeolite precursors as selective acidic ...

Aims: The study is aimed to develop an indigenous heterogeneous based catalyst and evaluate kinetic mechanism for the synthesis of ethyl acetate by esterification of acetic acid and ethanol. Study Design: Batch reactor system. Place and Duration of Study: Department of Pure and Industrial Chemistry, Faculty of Science, University of Port Harcourt, Rivers State. Nigeria. The study was carried out between February to August, 2011. Methodology: A sample of the natural clay was collected from the open clay deposit in Ezinachi, Okigwe Local Government Area, Imo state, Nigeria. The clay sample was washed and dried under sunshine for two days. Titanium pillared bentonite was produced by modification of natural bentonite clay using titanium pillaring solution at 500ᶿC. X-Ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) and BET gas sorption analysis were employed to characterize the pillared material. Esterification reactions were carried out in a batch mode using a three-necked round bottom glass flask of 250 ml capacity fitted with a reflux condenser and mercury in glass thermometer to monitor the temperature. Heating and stirring was achieved using a magnetic hot plate with a stirrer. Pre-determined amount of acetic acid (for 1:1, 2:1, 3:1, 4:1 acid: alcohol mole ratio) and the clay catalyst were charged into the reactor and heated to 90 ±0.5ºC. After the desired temperature has been reached, a known amount of ethanol preheated separately using heating mantle was added into the reactor. About 2 ml of the reaction mixture was taken immediately using Pasteur pipette and titrated against 0.1 M NaOH solution using phenolphthalein indicator. All the experimental runs were designed by varying the amount of the catalyst, the acid to alcohol mole ratios, and the reaction period to obtain various kinetic parameters while keeping the temperature constant for all the runs. Results: The result revealed that significant improvement on physicochemical characteristics of the bentonite samples occurred as a result of ...

Dupla diplomação UTFPR ; This work deals with the treatment of wastewater containing paracetamol, used as a model pharmaceutical emergent pollutant, by catalytic wet peroxide oxidation using clay-based materials as catalysts. The catalysts prepared in this work were clays activated through acid treatment and clays pillared with Co and Fe. For the preparation, natural clays from four different regions of Kazakhstan were used: Akzhar, Asa, Karatau and Kokshetau. The FTIR analysis showed that the pillared clays have a higher amount of iron in its structure when compared with the natural materials, suggesting that the intercalation of iron was successful. The N2 adsorption isotherms obtained were classified as Type II, typical of macroporous materials. The acid characterization showed that the procedures used for the preparation of the acid activated clays and of the pillared clays caused structural modifications. After the preparation and characterization, the pillared materials were tested in the degradation of paracetamol by catalytic wet peroxide oxidation (CWPO). Paracetamol concentration, hydrogen peroxide concentration and total organic carbon analysis (TOC) were followed against time. The material with the best activity was the Kokshetau pillared clay (KOP), with a complete conversion of the pollutant being obtained between 240 and 360 minutes of reaction, followed by a negligible iron leaching of 0.011 %. This leaching left the reaction system with a concentration of 0.089 mg/L of Fe, which is lower than the limit established by the European legislation for discharge in natural water courses (2 mg/L). Since the Kokshetau pillared clay presented the best result, other Kokshetau-based samples (activated, calcined and natural) were also tested in the CWPO of paracetamol. The higher efficiency of KOP in the CWPO of paracetamol can be explained by the fact that this material has a higher acidity, basicity and surface area when compared to the other pillared samples. ; Este trabalho aborda o tratamento de águas residuais que contém paracetamol, como poluente emergente modelo, por oxidação humida com peróxido de hidrogênio usando argilas como catalisadores. Os catalisadores a base de argila preparados neste trabalho foram as argilas ativadas mediante tratamento com ácido e as argilas pilarizadas com Cobalto e Ferro. Para o preparo, foram utilizadas argilas naturais de quatro regiões diferentes no Cazaquistão: Akzhar, Asa, Karatau e Kokshetau. A análise de FTIR mostrou que as argilas pilarizadas possuem uma maior quantidade de Ferro na sua estrutura quando comparado com os outros materiais, o que pode indicar que o processo de intercalação do metal na estrutura da argila obteve sucesso. Os resultados obtidos para as isotermas de adsorção de N2 foram usados para classificar o material como Tipo II, atribuída a materiais macroporoso. A caracterização ácida mostrou que os procedimentos usados para preparar a argila pilarizada e a argila ativada causaram modificações estruturais no material. Após a preparação e caracterização, as argilas pilarizadas foram testadas na degradação do paracetamol por meio da catálise húmida com peróxido de hidrogênio. A fim de avaliar a variação da concentração de paracetamol, peróxido de hidrogênio e a variação do teor de carbono orgânico total, amostras foram coletadas em diferentes tempos. O material com a melhor atividade foi a amostra de argila Kokshetau pilarizada (KOP), apresentando uma conversão completa do poluente entre 240 e 360 minutos de reação e uma quantidade de Ferro lixiviado de 0.011%. Essa porcentagem de lixiviação deixou o sistema reativo com uma concentração de Ferro de 0.089 mg/L, um valor menor que o valor limite estabelecido pela legislação (2 mg/L). Como entre as pilarizadas a amostra de Kokshetau demonstrou o melhor resultado, outras amostras a base de Kokshetau (ativada, calcinada e natural) também foram testadas na CWPO do paracetamol. O melhor desempenho da Kokshetau pilarizada pode ser justificado pelo fato de o material possuir uma maior quantidade de acidez, basicidade e área superficial com relação as outras argilas pilarizadas. ; To VALORCOMP for the financial support and to LSRE-LCM for the opportunity to acquire knowledge in the catalysis field.

[EN] A new route to obtain pillared, disordered or desilicated MWW-type zeolites was developed assisted by quaternary ammonium surfactants with different hydrocarbon tail size acting as swelling agents (C(12)TA(+), C(I6)TA(+), C(18)TA(+)) and TPA(+) both exchanged to their hydroxide forms instead of only one swelling agent (C(n)TA(+) or TPA(+)) in hydroxide form. Effect of surfactant concentration and swelling conditions were determinant to obtain MWW-type zeolites with different lamellar organization and spatial distribution of individual zeolitic layers. Specifically, soft swelling at 25 degrees C with C(12)TA(+) preserved layer structure reaching a final disordered/pillared structure while pillared structures are obtained in the case of materials swollen with C(16)TA(+) and C(18)TA(+). Aggressive swelling processes at 80 degrees C favored desilication, damaging the layers structure in case of C(12)TA(+) while pillared materials are obtained after swollen with C(16)TA(+) and C(18)TA(+) surfactants. It was proved that both swelling agents in hydroxide forms combining with swelling and pillaring procedure influenced on physico-chemical and morphological nature of MWW-type materials due to the particular conditions used. The obtained derivative MWW zeolites with different morphology, order and accessibility levels were firstly evaluated by catalytic dehydration of fructose to 5-hydroxymethylfurfural (5-HMF) showing superior activity compared to beta zeolites reported in literature. ; Anderson Joel Schwanke is grateful to CAPES Foundation and PDSE program (process number 99999.004779/2014-02) from Ministry of Education of Brazil. U.D and A.C acknowledge to the Spanish Government (Severo Ochoa program SEV-2012-0267 and MAT2014-52085-C2-1-P) and to the Generalitat Valenciana (Prometeo 11/2013-011) by the funding. The European Union is also acknowledged by ERC-AdG-2014-671093 - SynCatMatch. ; Schwanke, AJ.; Pergher, S.; Díaz Morales, UM.; Corma Canós, A. (2017). The influence of swelling agents molecular dimensions ...

This is the peer reviewed version of the following article: A. J. Schwanke, R. Balzer, C. Wittee Lopes, D. Motta Meira, U. Díaz, A. Corma, S. Pergher, Chem. Eur. J. 2020, 26, 10459, which has been published in final form at https://doi.org/10.1002/chem.202000862. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. ; [EN] In this work, an MWW-type zeolite with pillars containing silicon and niobium oxide was synthesized to obtain a hierarchical zeolite. The effect of niobium insertion in the pillaring process was determined by combining a controllable acidity and accessibility in the final material. All pillared materials had niobium occupying framework positions in pillars and extra-framework positions. The pillared material, Pil-Nb-4.5 with 4.5 wt % niobium, did not compromise the mesoporosity formed by pillaring, while the increase of niobium in the structure gradually decreased the mesoporosity and ordering of lamellar stacking. The morphology of the pillared zeolites and the niobium content were found to directly affect the catalytic activity. Specifically, we report on the activity of the MWW-type zeolites with niobium catalyzing the gas-phase oxidation of volatile organic compounds (VOCs), which is an important reaction for clean environmental. All produced MWW-type zeolites with niobium were catalytically active, even at low temperatures and low niobium loading, and provided excellent conversion efficiencies. ; A.J.S. thanks the CordenacAo de Aperfeicoamento de Pessoal de Nivel Superior-Brasil (CAPES)-Finance Code 001, the PDSE program (process number 99999.004779/2014-02) and the prof. Claudio Radtke from the PPGQ-UFRGS for the XPS analyses. C.W.L. is grateful to INOMAT/CAPES for a postdoctoral fellowship. U.D. thanks the funding by the Spanish Government (MAT2017-82288-C2-1-P). ; Schwanke, AJ.; Balzer, R.; Lopes, CW.; Meira, DM.; Díaz Morales, UM.; Corma Canós, A.; Pergher, S. (2020). A Lamellar MWW Zeolite With Silicon and Niobium Oxide ...

Relevant layered zeolites have been considered in this perspective article from the point of view of the synthesis methodologies, materials characterization and catalytic implications, considering the unique physico-chemical characteristics of lamellar materials. The potential of layered zeolitic precursors to generate novel lamellar accessible zeolites through swelling, intercalation, pillarization, delamination and/ or exfoliation treatments is studied, showing the chemical, functional and structural versatility exhibited by layered zeolites. Recent approaches based on the assembly of zeolitic nanosheets which act as inorganic structural units through the use of dual structural directing agents, the selective modification of germanosilicates and the direct generation of lamellar hybrid organic inorganic aluminosilicates are also considered to obtain layered solids with well-defined functionalities. The catalytic applications of the layered zeolites are also highlighted, pointing out the high accessibility and reactivity of active sites present in the lamellar framework. ; The authors thank financial support to Spanish Government by Consolider-Ingenio MULTICAT CSD2009-00050, MAT2011-29020-C02-01 and Severo Ochoa Excellence Program SEV-2012-0267. ; Díaz Morales, UM.; Corma Canós, A. (2014). Layered zeolitic materials: an approach to designing versatile functional solids. Dalton Transactions. 43(27):10292-10316. https://doi.org/10.1039/c3dt53181c ; S ; 10292 ; 10316 ; 43 ; 27 ; Mallouk, T. E., & Gavin, J. A. (1998). Molecular Recognition in Lamellar Solids and Thin Films. Accounts of Chemical Research, 31(5), 209-217. doi:10.1021/ar970038p ; Suslick, K. S., & Price, G. J. (1999). APPLICATIONS OF ULTRASOUND TO MATERIALS CHEMISTRY. Annual Review of Materials Science, 29(1), 295-326. doi:10.1146/annurev.matsci.29.1.295 ; Du, X., Zhang, D., Gao, R., Huang, L., Shi, L., & Zhang, J. (2013). Design of modular catalysts derived from NiMgAl-LDH@m-SiO2 with dual confinement effects for dry reforming of methane. ...

Bentonite clay from Maghnia (Algeria), very rich in montmorillonite (~ 90 %) purified and intercalated with pillars Al2O3, Al2O3-NiO and Al2O3-CoO, was applied as catalyst for the conversion of a mixture of castor oil-ethanol to biodiesel. The pillared clay with Al2O3-CoO (10%) led to 98% ester conversion. The highest yield of biodiesel production was obtained at 1/15 molar ratio of oil/ethanol, a temperature of 250 °C and 7.5 wt% of catalyst. This behaviour was ascribed to a synergetic effect of the largest surface area developed in the clay and the highest catalytic activity of cobalt in basic medium. The catalysts re-usability experiments revealed that the pillared clays were safely re-used three times without losing their original catalytic effectiveness. The kinetics calculations demonstrated that the transesterification of castor oil in an excess of alcohol using the pillared clay as catalyst followed a pseudo first order kinetics. The biodiesel produced exhibited comparable fuel properties as those of classical fossil diesel.