The beneficial effect of silica on the activity and thermal stability of PtCoFerrierite-washcoated cordierite monoliths for the SCR of NOx with CH4

PtCoFerrierite washcoated on a ceramic monolith is an active and selective catalyst for the SCR of NOx with methane. For our system, we found that the addition of a binder to the slurry used for the washcoat is necessary to improve the adherence and to obtain a selective catalyst. In our case, we used 2 wt.% of Cabot Silica. Ultrasound experiments used to comparatively evaluate the coating adherence showed that silica prevents the washcoat loss due to attrition. Similar monolithic catalysts, but prepared without a binder, resulted in catalysts with poor activity for NOx reduction, but still active for the deep oxidation of methane with oxygen. Monoliths washcoated without a binder showed both Pt segregation to the outer surface of zeolite crystals and formation of the non-selective Co3O4. Segregated Pt clusters and cobalt oxide promote the methane combustion with oxygen, thus leaving the NOx molecules unreacted. Moreover, due to Pt segregation, the necessary intimate contact between Pt and Co active species is not favored in this catalyst, which also contributes to the low selectivity to N2.Fil: Boix, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Lombardo, Eduardo Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Metal Organic Framework-Based Sustainable Nanocatalysts for CO Oxidation

The development of new catalytic nanomaterials following sustainability criteria both in their composition and in their synthesis process is a topic of great current interest. The purpose of this work was to investigate the preparation of nanocatalysts derived from the zirconium metal–organic framework UiO-66 obtained under friendly conditions and supporting dispersed species of non-noble transition elements such as Cu, Co, and Fe, incorporated through a simple incipient wetness impregnation technique. The physicochemical properties of the synthesized solids were studied through several characterization techniques and then they were investigated in reactions of relevance for environmental pollution control, such as the oxidation of carbon monoxide in air and in hydrogen-rich streams (COProx). By controlling the atmospheres and pretreatment temperatures, it was possible to obtain active catalysts for the reactions under study, consisting of Cu-based UiO-66-, bimetallic CuCo–UiO-66-, and CuFe–UiO-6-derived materials. These solids represent new alternatives of nanostructured catalysts based on highly dispersed non-noble active metals.Fil: Lozano, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Faroldi, Betina María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Ulla, Maria Alicia del H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

CO oxidation over Au supported on Mn-ZSM5 and Mn-MOR

Active gold catalysts for CO oxidation were obtained by the deposition-precipitation of gold on ZSM-5 and mordenite, both of them ion-exchanged with manganese. A strong promotion of Mn upon the activity of bimetallic Au/Mn catalysts was observed when compared with the monometallic Au-zeolites. In turn, when an in-situ reduction of the bimetallic catalysts was performed, a further increase in activity was observed. Characterizations suggested that smaller gold nanoparticles were stabilized in the bimetallic solids and that the reduction process caused a rearrangement of Au and Mn species on the catalyst surface.Fil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Boix, Alicia Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Hernández Martínez, Miguel Angel. Universidad Autónoma Metropolitana; Méxic

Confined growth of thin mordenite films into microreactor channels

This communication presents the production of a mordenite film growth totally confined into 350 μm wide microchannels on copper alloy plates for microreactor preparation. The growth is obtained in open channel configuration by secondary synthesis after 12 h of treatment over this highly thermal conductivity support. The confined growth presents a high overall quality. It is crystalline, uniform, and adherent; it totally covers the microchannels surface and has 5 μm. These properties are confirmed by XRD, SEM and EPMA characterizations.Fil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Novel binderless zeolite-coated monolith reactor for environmental applications

A novel structured catalyst based on a binderless zeolite film was developed onto a cordierite monolith. The zeolitic film was obtained performing a binderless washcoating which was followed by a hydrothermal treatment, which resulted in a coating with hybrid physicochemical properties, having a porous washcoat-like microstructure with an intergrowth between the aggregates. This combination confers to the zeolite coating an open structure which is an advantage of washcoats and a high mechanical stability characteristic of the zeolite growths. It should be emphasized that these desired properties are obtained without the use of binders. The physico-chemical properties were investigated through MIP (mercury intrusion porosimetry), SEM (scanning electron microscopy), ultrasonic adherence tests, NO-TPD (temperature-programmed desorption of NO) and EPMA (electron probe microanalysis). The catalytic properties of the monolith were evaluated in the selective catalytic reduction of NOx at high spatial velocities, showing promising results.Fil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

Sonocrystallization of zeolitic imidazolate frameworks (ZIF-7, ZIF-8, ZIF-11 and ZIF-20)

Zeolitic imidazolate frameworks ZIF-7, ZIF-8, ZIF-11 and ZIF-20 have been synthesized by sonocrystallization. In general, crystals obtained at lower temperatures and shorter times are smaller and have a narrower size distribution than those achieved by conventional solvothermal synthesis. Moreover, crystallization curves have been calculated from the XRD patterns and the Gualtieri?s model has been applied to simulate the extent of crystallization as a function of time. According to the parameters calculated, for ZIF-8 the nucleation rate controls the synthesis reaction, while for ZIF-11 and ZIF-20 both growth and nucleation rates are similar.Fil: Seoane, Beatriz. Universidad de Zaragoza. Instituto de Nanociencia de Aragón; EspañaFil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Téllez, Carlos. Universidad de Zaragoza. Instituto de Nanociencia de Aragón; EspañaFil: Coronas, Joaquin. Universidad de Zaragoza. Instituto de Nanociencia de Aragón; Españ

Microreactors based on CuO/CeO2/zeolite films synthesized onto brass microgrids for the oxidation of CO

Microreactors based on Cu, Ce oxides dispersed onto zeolite films grown on brass microgrids were developed. Secondary synthesis conditions were regulated in order to obtain thin, homogeneous and adherent coatings of mordenite to which Cu and Ce were later incorporated. The systems were characterized by XRD, SEM-EPMA, H2-TPR, LRS and XPS. The catalytic coatings were mechanically and chemically stable under reaction. Cu, Ce/zeolite microreactors were evaluated in the CO total oxidation (COTox) and in the preferential CO oxidation (COProx) showing a superior performance when compared with the same powder catalyst.Fil: Pérez, Nicolás C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera"; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera"; ArgentinaFil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera"; Argentin

Secondary growth of ZIF-8 films onto copper-based foils. Insight into the surface interactions

The film growth of the zeolitic imidazolate framework-8 on a copper-based substrate is reported for the first time in the literature. The growth mechanism on copper foils is analyzed, and it is demonstrated that during synthesis the development of the metal-organic framework (MOF) film is sensitive to the interactions produced between the support surface, the solvent and the reactants. In order to compare the surface interactions during synthesis, Fecralloy foils, porous alumina disks and macroporous cordierite monoliths are also analyzed. The physicochemical properties of the materials are evaluated by XRD, SEM, EPMA, AAS, DRIFT and XPS. In DMF-based media, no ZIF-8 film develops on the copper surface due to unfavorable interactions that make its growth non selective. At the same time, the formation of a dense ZnO layer is favored, this layer being promoted by decomposition products of the solvent and the zinc reagent. When water-based media are used, those interactions are modified thus avoiding the formation of oxide, but the growth kinetics of the ZIF-8 film is still low. On the other hand, when using mixtures based on methanol with the addition of acetate, continuous, uniform, and adherent ZIF-8 films can be obtained. Such films develop preferential crystallographic orientations in planes {200} and {110}, have thicknesses between 5 to 10 microns and good mechanical and thermal stability. The results obtained provide a platform for the obtention of ZIF-8 films on copper structures, which is relevant for the development of new structured catalysts based on MOFs.Fil: Papporello, Rocío L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Influence of the solvent in the synthesis of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals at room temperature

The effect of the solvent on the synthesis process and on the nanocrystal characteristics of the zeolitic imidazolate framework-8 (ZIF-8) was investigated. A synthesis protocol at room temperature employing a series of aliphatic alcohols, water, dimethylformamide and acetone was employed. The results show that the solvent modifies the evolution of the reaction, altering the crystallization rates and nanocrystal sizes. Its hydrogen bond donation ability is the main factor that governs this effect. More precisely, the solvent modulates the formation of ZIF-8 nanocrystals with sizes in the range between 15 and 42 nm. When synthesized in alcohol and acetone, these nanocrystals form globular aggregates with sizes between 130 and 420 nm. In contrast, under the same synthesis conditions, when using water or dimethylformamide the ZIF phase is not developed. In alcohols other than methanol, the crystals develop pill-shaped morphologies with poorly defined facets. Moreover, a markedly fast growing kinetics is verified in these alcohols, leading to an ultra-fast crystallization of ZIF-8 in about 60 s. These findings provide new information about the role of the solvent in the synthesis process of nanoZIF-8, which can be useful for controlling the crystallization rates and nanocrystal sizes of this material.Fil: Bustamante, Eugenia L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Fernandez, Jose Luis. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Programa de Electroquímica Aplicada e Ingeniería Electroquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; Argentin

Cu,Ce/mordenite coatings on FeCrAl-alloy corrugated foils employed as catalytic microreactors for CO oxidation

The aim of this work was to study different strategies for the synthesis of mordenite coatings on thin FeCrAl alloy foils in order to obtain adherent, stable and homogeneous films for their use as catalytic microreactors. For this purpose, the substrate pretreatments and growth conditions of the films by secondary synthesis were investigated. The best results were obtained by applying a brief calcination of the foils at 700 ºC that developed a smooth alumina film with hydrophilic properties, followed by immersion in a 0.4 wt.% aqueous solution of the cationic polymer poly-(diallyldimethilammoniumchloride), PDDA. The subsequent seeding with diluted nanocristal suspensions (2 g L) of Na-mordenite allowed the development of zeolite films with the desired properties and the additional benefit of a marked preferential growth on the metallic surface at the expense of a negligible growth within the synthesis solution. Finally, homogenous zeolite films were obtained in micro-corrugated foils, after which Cu and Ce were incorporated as catalytic ingredients and used in a microreactor for the CO oxidation reaction under different conditions.Fil: Pérez, Nicolas C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera"; ArgentinaFil: Miro, Eduardo Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera"; ArgentinaFil: Zamaro, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones En Catalisis y Petroquímica "ing. Jose Miguel Parera"; Argentin