Ferrierite Type Zeolite Research Articles

Reversible Multi-Complexation of CO2 to Alkaline Earth Metal Ion-Pair at 400 ppm and 298 K.

The efficient capture of low-pressure CO2 remains a significant challenge due to the lack of established multi-complexation of CO2 to active sites in microporous materials. In this study, we introduce a novel concept of reversible multi-complexation of CO2 to alkaline earth metal (AEM) ion pairs, utilizing a host site in ferrierite-type zeolite (FER). This unique site constrains two AEM ions in proximity, thereby enhancing and isotopically spreading their electrostatic potentials within the zeolite cavity. This electrostatic potential-engineered micropore can trap up to four CO2 molecules, forming M2+-(CO2)n-M2+ (n = 0-4, M = Ca, Sr, Ba) complexes, where each CO2 molecule is stabilized by interactions between terminal oxygen (Ot) in CO2 and the AEM ions. Notably, the Ba2+ pair site exhibits higher thermodynamic stability for multiple adsorptions due to the optimal binding mode of Ba2+-Ot-Ba2+. Through high-accuracy energy calculations, we established the relationship among structure, CO2 uptake, and operating temperature/pressure, demonstrating that the Ba2+ pair site can reversibly capture four CO2 molecules even at concentrations as low as 400 ppm and at 298 K. The findings in the present study provide a new direction for developing efficient CO2 adsorbents.

Synthesis of ferrierite-type zeolite by microwave method using ethylenediamine as an organic structure-directing agent

A new method for the synthesis of ferrierite-type zeolite has been developed using microwave irradiation in the presence of structure-directing agents (templates). The physicochemical characteristics of the synthesized zeolites were investigated by X-ray diffraction analysis, low-temperature nitrogen adsorption–desorption and SEM-EDX. When comparing the synthesis products, it was found that microwave irradiation significantly reduces the crystallization time of the synthesized zeolites compared to traditional hydrothermal treatment

Preparation and catalytic properties of a novel aluminosilicate zeolite with intersecting 14*12-Ring pore sizes

Abstract A novel ferrierite type zeolite named as IEZ-Al-PLS-3(S4R) with pore sizes of 14 × 12-ring (R) was post synthesized by simply interlayer silylation of lamellar precursor Al-PLS-3 taking 1,3,5,7-tetramethylcyclosilone (TMCS) as silane. Its catalytic properties were tested by isomerization/disproportionation of m-xylene, alkylation/acylation of anisole with benzyl alcohol/acetic anhydride. The catalytic performance of IEZ-Al-PLS-3(S4R) was compared with Al-PLS-3 (10 × 8-R) and IEZ-Al-PLS-3(1Si) (12 × 10-R) which were prepared by calcination or silylation using dimethoxydimethylsilane (DEDMS) as silane of as made Al-PLS-3 respectively. Since these materials have the same laminates composition, the differences of catalytic performance can be considered as the result of different pore sizes. We also prepared conventional 10-R zeolite ZSM-5 and 12-R zeolite Beta for control experiments. IEZ-Al-PLS-3(S4R) showed even higher catalytic activities than Beta as a result of its enlarged 14-R pore size.

Tailoring selectivity in the liquid-phase isomerization of α-pinene on dealuminated ferrierite-type zeolites

Abstract Ferrierite-type zeolite (Zeolyst Intern.) with Si/Al = 10 was dealuminated sequentially using solutions of hydrochloric acid of different concentrations. The course of dealumination was followed by XRD, XPS, sorption of nitrogen, scanning electron microscopy, FTIR, and solid-state 29Si, 27Al and 1H MAS NMR. The dealuminated samples retained high crystallinity and revealed good sorption properties. The tetrahedrally coordinated aluminium in ferrierite was distributed between TB sites located in the main channels and TA ones siting in hidden positions. It was shown that dealumination removed aluminium from ferrierite in a non-random manner; up to 60% of aluminium was removed from TB and up to 19-% from TA sites. The amount and strength of Bronsted acid sites decreased with dealumination. The samples were tested in the liquid-phase isomerization α-pinene at 348–363 K; camphene and limonene were the main products. The initial reaction rates and turnover frequencies have been estimated and compared to other zeolite catalysts. The selectivity to camphene and limonene was in the range of 77–98.9 %.

Catalytic and physicochemical properties of modified natural clinoptilolite

A natural specimen from the deposit at Kučin (Slovakia), rich in clinoptilolite type zeolite, was dealuminated using HCl solutions of increasing concentration (0.05–11.5M). The samples were characterized by XRD, sorption of nitrogen, TPD of ammonia, FT IR and NMR spectroscopies. The preparations modified under mild conditions (acid concentration, temperature of dealumination) retained largely their crystallinity and acidity, and were active in the liquid phase isomerization of α-pinene. Upon more severe treatments, the samples became partially amorphous and lost their catalytic activity. The kinetics of α-pinene isomerization was studied over the most active catalysts. The reaction rate constants and apparent energies of activation were obtained. Initial reaction rates over the clinoptilolite type catalysts were compared with other acidic catalysts, including ferrierite-type zeolites.

Catalysts based on ferrierite for the selective hydrocracking of n-hexane

Supported platinum catalysts based on ferrierite type zeolite with Pt content in the range of 1.3–2.8 wt % are prepared. The localization of Pt in zeolite channels is studied for the first time. It is shown that the platinum localized in them increases the yield of products from the selective hydrocracking of n-hexane. Platinum on the outer surface of the zeolite crystals participates in the transformation of n-hexane in the direction of forming hydrocarbons with isomeric structure. The catalysts can be used to improve the octane rating of reformed gasoline, owing to the selective removal of low-octane n-paraffin hydrocarbons and the increase of the portion of high-octane isoparaffin hydrocarbons in the catalytic reforming gasolines.

Transformations of monoterpene hydrocarbons on ferrierite type zeolites

Transformations of α-pinene and limonene over hydrogen forms of commercial ferrierite type zeolites of different origin (Tosoh Corp. and Zeolyst Intern.) have been studied in the liquid phase at 313–363K. The catalysts were characterized by XRD, sorption of nitrogen, scanning electron microscopy, FTIR and 27Al &1H MAS NMR. The concentration of Brønsted acid sites has been determined by 1H MAS NMR and FTIR quantitative measurements, while their strength was estimated by adsorption of CO. The liquid-phase isomerization of α-pinene proceeds smoothly on the two zeolite catalysts, and the initial reaction rates have been compared. Camphene and limonene were the main products, while the selectivity to these hydrocarbons differed. Isomerization of pure limonene was also studied, showing large difference in activity over the two ferrierite catalysts. The selectivity of α-pinene transformations has been rationalized in terms of retarded consecutive isomerization of limonene over the zeolite from Zeolyst.

Impact of Controlling the Site Distribution of Al Atoms on Catalytic Properties in Ferrierite-Type Zeolites

Zeolites with the ferrierite (FER) topology are synthesized using a combination of tetramethylammonium (TMA) cations with differently sized cyclic amines (pyrrolidine (Pyr), hexamethyleneimine (HMI), and 1,4-diazabicyclo[2.2.2]octane (DAB)). Using these organic structure-directing agents (SDAs), low Si/Al ratios and concentrated synthesis mixtures favor the crystallization of FER materials. Increasing the size of the cyclic amine or decreasing the aluminum content leads to the crystallization of other phases or the creation of excessive amounts of connectivity defects. TMA cations play a decisive role in the synthesis of the FER materials, and their presence allows the use of HMI to synthesize FER. Proton MAS NMR is used to quantify the accessibility of pyridine to acid sites in these FER samples, where it is found that the FER + HMI + TMA sample contains only 27% acid sites in the 8-MR channels, whereas FER + Pyr and FER + Pyr + TMA contain 89% and 84%, respectively. The constraint index (CI) test and the carbonylation of dimethyl ether (DME) with carbon monoxide are used as probe reactions to evaluate how changes in the aluminum distribution in these FER samples affect their catalytic behavior. Results show that the use of Pyr as an SDA results in the selective population of acid sites in the 8-MR channels, whereas the use of HMI generates FER zeolites with an increased concentration of acid sites in the 10-MR channels.

Characterization of (Fe,Al)FER synthesized in presence of ethylene glycol and ethylene diamine

(Fe,Al)Ferrierite type zeolite was hydrothermally crystallized in a gel system of sodium aluminosilicate with ethylene glycol a nitrogen-free organic compound, as well as, ethylene diamine. The zeolite crystals obtained were characterized by X-ray diffractometry (XRD), thermal analysis (TGA–DTA), electron scanning microscopy (SEM), chemical analysis, N 2 adsorption/desorption at 77 K and 29Si–, 27Al–, 13C–, and 1H NMR spectroscopy. Fe atoms essentially occupy framework positions and rather high amounts of SiOH defect groups are present in the as-made samples.

Computational and FTIR spectroscopic studies on carbon monoxide and dinitrogen adsorption on a high-silica H-FER zeolite

Adsorption (at a low temperature) of carbon monoxide and dinitrogen on a high-silica ferrierite-type zeolite (H-FER, Si : Al = 27.5 : 1) was investigated by means of variable temperature infrared spectroscopy and theoretical calculations at the periodic DFT level. This combined experimental and computational approach led to detailed characterization of several types of hydrogen-bonded OHCO and OHN(2) complexes, formed by interaction between the adsorbed molecules and the Brønsted acid OH groups of the zeolite. CO or N(2), forming linear complexes with OH groups pointing towards a sufficiently ample void space, show the largest adsorption enthalpy which was found to be in the (approximate) range of -25 to -29 kJ mol(-1) for CO and -15 to -19 kJ mol(-1) for N(2). Less stable OHCO or OHN(2) complexes can be formed when either the Brønsted acid OH group is involved in intra-zeolite hydrogen bonding or when the free space available is too small to allow formation of linear complexes without previous re-location of the proton of the OH group involved. The details of experimental IR spectra in the O-H, C-O, and N-N stretching regions could be interpreted on the basis of good agreement between experimental and calculated results.

Cooperative Effect of Sodium and Potassium Cations on Synthesis of Ferrierite

Ferrierite type zeolite can be synthesized without using any organic structure-directing agent from Na- or (Na, K)- or K-aluminosilicate system. (Na, K)-ferrierite is synthesized from wide range of OH/SiO2 region of the reactant mixture compared with Na- and K-ferrierite. The crystallization process of ferrierite in each system is investigated in detail by X-ray diffraction and Raman spectroscopy. The role of potassium and sodium cations and cooperative effect of two cations in the formation of the framework of ferrierite are elucidated.

The influence of the initial acidity of HFER on the status of Co species and catalytic performance of CoFER and InCoFER in CH 4-SCR-NO

The role of the initial acidity of ferrierite type zeolite on the status of cobalt and the catalytic activity of CoFER and InCoFER was investigated. Two FER zeolites were used: NH 4FER without any pretreatment (FER-1) and the same zeolite, dehydroxylated at 825 K (FER-2). Dehydroxylation removed most of the Si–OH–Al groups, therefore the resulting zeolite revealed practically no ion exchange capacity. The status of cobalt was followed by IR spectroscopy with probe molecules: CO (a probe for Co 2+) and NO (a probe for Co 3+). The introduction of cobalt by solid-state ion exchange produced divalent cobalt in exchange positions and in the form of oxide-like clusters, their respective concentration was determined by quantitative IR experiments of CO sorption. The amount of Co 3+, present in CoFER-1 and InCoFER-1, was also determined. All these forms of cobalt were practically absent from CoFER-2 and InCoFER-2. The NO conversion and selectivity to N 2 of CoFER-2 in CH 4-SCR-NO was poor, indicating the essential role of the initial acidity of the ferrierite matrix on the formation of catalytically active Co species. The introduction of indium into CoFER only slightly increased the NO conversion and shifted the reaction path from NO 2 towards N 2 formation for FER-1, while greatly improved the catalytic performance of the FER-2 series.

Isomerization of α-pinene over dealuminated ferrierite-type zeolites

Isomerization of α-pinene was performed on a series of dealuminated ferrierite (FER)-type zeolites in liquid phase at 363 K using a batch reactor. The course of zeolite dealumination was followed in detail using 29Si, 27Al, 1H MAS NMR, XRD, FTIR, and sorption of nitrogen. The ammonium form of FER was dealuminated with aqueous solutions of HCl. While retaining the crystallinity of the zeolite particles, the treatments removed up to 53% of the tetrahedrally coordinated aluminum atoms from the FER framework. According to 29Si MAS NMR studies, the framework aluminum atoms located at the 10-membered rings in the main channels of FER (T B sites) were depleted preferentially from their positions. Even relatively mild dealumination of FER led to an active catalyst containing both Brønsted and Lewis centers, yielding up to 97% conversion of α-pinene at 363 K, in contrast to the 72% observed for the parent hydrogen form. Such catalytic behavior was discussed in terms of the conversion of a reactant inside micropores of the zeolite catalyst, on Brønsted acid centers with enhanced strength located probably in the vicinity of Lewis sites. The selectivity toward camphene and limonene changed smoothly with the dealumination level; thus, a higher selectivity toward limonene was observed at the expense of camphene formation with increasing the n Si / n Al ratio of the catalysts. The selectivity toward camphene and limonene was close to 85% for all of the materials studied. The initial rates of α-pinene transformations over FER-type materials exceeded those observed for other catalytic systems, heteropoly acid/SiO 2 and H 2SO 4/ZrO 2. This study demonstrates the successful application of a medium-pore zeolite for the catalytic transformation of α-pinene in liquid phase.

In/Co-ferrierite: A highly active catalyst for the CH4-SCR NO process under presence of steam

A series of monometallic (In, Co) and bimetallic (In/Co and Co/In) catalysts supported on ferrierite type zeolite were tested in the selective catalytic reduction of nitric oxide, in the presence of methane and excess of oxygen. All the catalysts were prepared by contact-induced ion exchange. A strong synergistic effect was observed for the catalysts containing both indium and cobalt, in comparison with the monometallic samples. For these bimetallic catalysts, a very high selectivity to nitrogen and rather efficient fuel economy were observed under the standard reaction conditions (NO=1000ppm, CH4=2000ppm, O2=4%, H2O=2500ppm). Moreover, the In/Co-ferrierite catalyst displays significant stability under a prolonged test (∼200h) in the presence of 2.5% of steam: the activity dropped rather moderately but was completely restored if steam supply was cut off, while the selectivity of the reaction was not affected in the whole temperature range scanned (300–500°C). The study suggests that a redox-type promotional effect of Co species on NO oxidation may be responsible of the strong synergistic effect detected in bimetallic In–Co formulations.

Synthesis of ferrierite coatings on the FeCrAl substrate

Zeolite coatings on metal substrates are highly desirable materials that can be used as efficient catalysts. In this paper we report on preparation of ferrierite type zeolite coatings on a pre-oxidized metal substrate. Ferrierite was chosen due to its unique catalytic properties, including potential application in nitrogen oxides removal. FeCrAl ferritic steel was used as a substrate. The FeCrAl foil was oxidized in air at 800 °C. The in situ synthesis of ferrierite on the FeCrAl substrate and in bulk were studied using XRD, laser diffraction (LD) and scanning electron microscopy (SEM). Various conditions were applied for coatings preparation, including static and dynamic syntheses, variable nucleation time and type of a gel used. The kinetics of ferrierite crystallization is also reported.

Catalytic properties of dealuminated ferrierite type zeolite studied in transformations of m-xylene : Part 2

The ammonium form of ferrierite (obtained from K,Na-ferrierite, Tosoh) was modified with aqueous solution of hydrochloric acid of different concentration. It has been demonstrated that ferrierite is amenable to HCl solution treatment, while retaining its high crystallinity (XRD, SEM). Dealumination proceeded smoothly and 60% of aluminium was easily removed from the sample just upon 0.25 M HCl treatment. 29Si NMR revealed that during the acid treatment the aluminium atoms were removed preferentially from Si(2Al) and Si(1Al) T B positions. Acidity of the samples was assessed by sorption of CO and ammonia and using FT IR spectroscopy. Studies of m-xylene transformations showed increased activity of the samples with increasing level of dealumination. Such behaviour was attributed to a particular morphology of the parent ferrierite. Dealumination of zeolite with the plate-like morphology yields a highly active material, coupled with high para-selectivity after the first acid treatment.

Dealumination of ferrierite type zeolite: Physicochemical and catalytic properties

Dealumination of ferrierite type zeolite was studied using aqueous solutions of hydrochloric acid of different concentrations. The course of the reaction was monitored by XRD, sorption, NMR, XPS and TPD of ammonia. The catalytic properties were studied using m-xylene transformations as a test reaction. A mild treatment with the diluted acid exerts a significant effect on the reaction path. The selectivity towards p-xylene formation on the dealuminated samples was strongly preferred and much greater than thermodynamic equilibrium data. Simultaneously, disproportionation of m-xylene yielding toluene and trimethylbenzenes was suppressed.

Synthesis of Ferrierite-Type Zeolite in the Presence of a Catalytic Amount of Pyrrolidine and Sodium Bis(2-ethyhlhexyl) Sulfosuccinate

Synthesis of ferrierite (FER) type zeolite with varying Si to Al ratios in the presence of a catalytic amount of pyrrolidine and sodium bis(2-ethylhexyl) sulfosuccinate (AOT) in aqueous media is reported. The surfactant moieties direct pyrrolidine molecules in a particular fashion, resulting in a sixfold decrease in the required amount of template as compared to conventional procedure, for FER crystallization. The product obtained was highly crystalline and pure. In the presence of AOT alone, ferrierite co-crystallized with the ZSM-5 phase, indicating AOT is not acting as a structure-directing agent and a small concentration of pyrrolidine (∼2 wt%) template is essential for the ferrierite crystallization. A scanning electron micrograph showed uniformity in crystals (average 2–3 μm) consisting of broad plate type morphology. The crystal structure of FER (AOT/Py) maintains structural integrity until about 1000°C. FER (AOT/Py) has been further characterized by employing XRD, XRF, IR, and TG/DTA techniques.

Synthesis and Characterization of Ferrierite-Type Zeolite in the Presence of Nonionic Surfactants

Pure-phase ferrierite (FER) zeolite has been synthesized in the presence of small amounts of nonionic surfactants, Tween 20 and Tween 80. The input SiO2/Al2O3 molar ratio has been varied over a range of 25 to 150. The results confirm that a small amount of pyrrolidine acts as a template and is necessary. The effects of varying concentration of surfactant on ferrierite crystallization and output SiO2/Al2O3 molar ratio are reported. The results also show that in the absence of pyrrolidine, ZSM-5 cocrystallized with FER, whereas in the absence of a nonionic surfactant the yield and crystallization of FER are very poor. The XRF analysis shows the changes in SiO2/Al2O3 output molar ratios as the surfactant concentration changes. The XRD data show that the samples are fully crystalline and pure. The TG/DTA of the sample shows its structural stability. The scanning electron microscopy results show changes in particle size with varying concentration of nonionic surfactant.

Affinity Study of Organics on Siliceous Ferrierite Type Zeolite

Thermal analyses were used to study the loading and the affinity of organic adsorbates on siliceous ferrierite type zeolite, which possesses perfect framework and high hydrophobic character after calcination for removing the template in the as-synthesized form. Twenty organic compounds with various functional groups, i.e., n-butane, n-pentane, n-hexane, n-heptane, methanol, ethanol, 1-propanol, 1-butanol, methylamine, ethylamine, n-propylamine, n-butylamine, formic acid, acetic acid, formaldehyde, acetaldehyde, diethyl ether, acetone, methyl formate, and ethyl formate, were investigated as the adsorbate. The AT index, defined as the value of Tdesorption − Tbp, was determined and used to compare the affinity of the organic compounds toward the zeolite. Organic molecules containing frameworkphilic functional groups such as alkylamines show high AT values. The oxygen-containing frameworkphobic functional groups such as alcohols and organic acids show lower AT values. The effect of other functional groups and...