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In the dimethyl ether (DME)-to-olefin (DTO) reaction over 20 types of P-loaded ferrierite zeolites with different P loading amounts, the synthesis of n-butenes such as 1-butene, trans-2-butene, and cis-2-butene was investigated to maximize the n-butene yield by optimizing the P loading amount. The zeolites were characterized using X-ray diffractometry (XRD), N2 adsorption-desorption isotherms, and NH3 temperature-programmed desorption (NH3-TPD). Micropore and external surface areas, total pore and micropore volumes, and weak and strong acids affected the DTO reaction's characteristics. The P-loaded ferrierite zeolite with a P loading of 0.3 wt.% calcined at 500 °C exhibited an n-butene yield of 35.7 C-mol%, which exceeds the highest yield reported to date (31.2 C-mol%). Multiple regression analysis using the obtained data showed that the strong acid/weak acid ratio and total pore volume had a high correlation with the n-butene yield, with a contribution rate of 64.3%. Based on the multiple regression analysis results, the DTO reaction mechanism was discussed based on the proposed reaction model involving the dual-cycle mechanism. [ABSTRACT FROM AUTHOR]

Abstract In this research, the magnetic solid acid nanocatalyst based on ferrierite has been prepared and used as catalyst for the green synthesis of some [1,3]-oxazine derivatives in water at room temperature. The synthesized compounds were obtained in high to excellent yields after short reaction times and the structure of synthesized products were investigated by spectroscopic methods such as: FT-IR, 1H NMR and 13C NMR. The prepared magnetic solid acid catalyst was characterized using XRD, FT-IR, FE-SEM, EDX, elemental mapping, TGA and VSM analysis methods. Magnetic catalyst has easy separation ability, which leads to better and easier recycling. The preparation and synthesis of [1,3]-oxazine derivatives were carried out at room temperature in the presence of M-FER/TEPA/SO3H. Easy workup, green solvent (water) and also short reaction times with high to excellent yield of products, are some of advantageous of presented method. Docking calculations on the structure of the synthesized compounds proved their medicinal properties against breast cancer cells.

In this research, the magnetic solid acid nanocatalyst based on ferrierite has been prepared and used as catalyst for the green synthesis of some [1,3]-oxazine derivatives in water at room temperature. The synthesized compounds were obtained in high to excellent yields after short reaction times and the structure of synthesized products were investigated by spectroscopic methods such as: FT-IR, 1H NMR and 13C NMR. The prepared magnetic solid acid catalyst was characterized using XRD, FT-IR, FE-SEM, EDX, elemental mapping, TGA and VSM analysis methods. Magnetic catalyst has easy separation ability, which leads to better and easier recycling. The preparation and synthesis of [1,3]-oxazine derivatives were carried out at room temperature in the presence of M-FER/TEPA/SO3H. Easy workup, green solvent (water) and also short reaction times with high to excellent yield of products, are some of advantageous of presented method. Docking calculations on the structure of the synthesized compounds proved their medicinal properties against breast cancer cells. [ABSTRACT FROM AUTHOR]

An economic route for the generation of hydrogen and utilization of carbon nanofibers (CNFs) was achieved by CH 4 cracking over 20 wt%Ni/FER catalyst. The deactivated catalyst demonstrated electrical conductivity and hydrogen storage properties. TEM images displayed open mouths of CNFs and XRF data showed nearly 70% of nickel was recovered from the deactivated catalyst. Impedance studies of the CNFs exhibit prominence as battery electrodes due to their significant conductivity in the presence of nickel. While the hydrogen storage capacity was around 0.151 mmol (g cat)−1 of H 2 on the obtained CNFs, it was increased to 0.361 mmol (g cat)−1 upon Ni recovery from the CNFs. A seven-fold increase in the H 2 storage of ∼0.862 mmol (g cat)−1 was obtained upon Li doping, exhibiting its distinct property as a hydrogen storage material. The fresh, reduced, used, and deactivated catalysts were characterized by BET-SA, H 2 -TPR, XRD, Raman spectroscopy, TEM, and H 2 pulse chemisorption and Ni/FER was established as an economically viable catalyst for high rates of H 2 and CNF production. [Display omitted] • Cracking of CH 4 produced pure H 2 and CNFs over Ni/Ferrierite. • Deactivated Ni/Ferrierite catalyst showed good electrical conductivity. • Ni recovered deactivated Ni/Ferrierite exhibited excellent H 2 storage capacity. • H 2 storage capacity was tremendously improved upon Li doping. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction by methanol (Methanol-SCR) on FER zeolite is a promising technology for the deNOx treatment of flue gas with a high concentration of sulfur. However, the resistance to alkali metal and sulfate ions is crucial for the practical application of Methanol-SCR catalysts. In this study, we investigated the poisoning mechanism of H-FER zeolite by K+ and sulfate ions. It was observed that K+ ions induce deactivation at high temperatures, whereas the decline at low temperatures (< 320 °C) can be attributed mainly to sulfate ions. Furthermore, surface modification of H-FER zeolite with metal oxide nanoparticles, such as alumina, has proved to be an effective method for improving its potassium sulfate resistance performance by preventing the diffusion of sulfate into zeolite pores. [ABSTRACT FROM AUTHOR]

Iron‐containing zeolite‐based catalysts play a pivotal role in environmental processes aimed at mitigating the release of harmful greenhouse gases, such as nitrous oxide (N2O) and methane (CH4). Despite the rich iron chemistry in zeolites, only a fraction of iron species that exhibit an open coordination sphere and possess the ability for electron transfer are responsible for activating reagents. In addition, the splitting of molecular oxygen is facilitated by bare iron cations embedded in zeolitic matrices. Mössbauer spectroscopy is the ideal tool for investigating the valency and geometry of iron species in zeolites because it leaves no iron forms silent and provides insights into in‐situ processes. This review is dedicated to the utilization of Mössbauer spectroscopy to elucidate the nature of the extra‐framework iron centers in ferrierite (FER), beta‐structured (*BEA), and ZSM‐5 zeolite (MFI) zeolites, which are active in N2O decomposition and CH4 oxidation through using the active oxygen derived from N2O and O2. In this work, a structured summary of the Mössbauer parameters established over the last two decades is presented, characterizing the specific iron active centers and intermediates formed upon iron's interaction with N2O/O2 and CH4. Additionally, the impact of preparation methods, iron loading, and the long‐term stability on iron speciation and its redox behavior under reaction conditions is discussed. [ABSTRACT FROM AUTHOR]

The zeolite-catalyzed conversion of DME into chemicals is considered environmentally friendly in industry. The periodic density functional theory, statistical thermodynamics, and the transition state theory are used to study some possible parallel reactions about the hydrogen-bonded DME over zeolite ferrierite. The following are the key findings: (1) the charge separation probably leads to the conversion of a hydrogen-bonded DME into a dimethyl oxonium ion (i.e., DMO+ or (CH3)2OH+) with a positive charge of about 0.804 e; (2) the methylation of DME, CH3OH, H2O, and CO by DMO+ at the T2O6 site of zeolite ferrierite shows the different activated internal energy (∆E≠) ranging from 18.47 to 30.06 kcal/mol, implying the strong methylation ability of DMO+; (3) H-abstraction by DMO+ is about 3.94–15.53 or 6.57–18.16 kcal/mol higher than DMO+ methylation in the activation internal energy; (4) six DMO+-mediated reactions are more likely to occur due to the lower barriers, compared to the experimental barrier (i.e., 39.87 kcal/mol) for methyl acetate synthesis; (5) active intermediates, such as (CH3)3O+, (CH3)2OH+, CH3CO+, CH3OH2+, and CH2=OH+, are expected to appear; (6) DMO+ is slightly weaker than the well-known surface methoxy species (ZO-CH3) in methylation; and (7) the methylated activity declines in the order of DME, CH3OH, H2O, and CO, with corresponding rate constants at 463.15 K of about 3.4 × 104, 1.1 × 102, 0.18, and 8.2 × 10−2 s−1, respectively. [ABSTRACT FROM AUTHOR]

The adsorption, temperature-programmed desorption, and carbonylation of dimethyl ether (DME) in the presence of mordenite and ferrierite (SiO2/Al2O3 ≈ 20, Zeolyst International) is studied. The effect of introducing Cu, Co, and Mg cations by ion exchange is discussed. Dimethyl ether carbonylation is conducted at 200°С, a pressure of 3 MPa, and a space velocity of 8000 mL g–1 h–1 in the following mixture (vol %): DME, ⁓2.2; CO, 92.8–95.5; and the rest, N2. After an induction period, the methyl acetate content in the presence of mordenite is about 4–5 times higher than that in the presence of ferrierite. Water, methanol, and hydrocarbons are formed in trace amounts. The introduction of Cu, Co, and Mg cations into mordenite by ion exchange (single ion-exchange run, cation/Al ratio of no more than 35%) leads to an increase not only in stability, but also in activity in the DME carbonylation reaction. It is found that an increase in the content of copper (from 1.19 to 2.23 wt %) and magnesium (from 0.62 to 1.8 wt %) has different effects on activity. It increases in the case of copper and decreases in the case of magnesium. The prereduction of a copper-exchanged mordenite leads to the appearance of metallic copper particles on the surface of the mordenite crystallites and a decrease in activity. According to in situ diffuse reflectance infrared spectroscopy, the introduction of magnesium cations by three ion-exchange runs leads to a significant decrease in the number of Brønsted acid sites (BASes) in both the 12-MR and 8-MR channels of the mordenite. The catalytic characteristics of ferrierite hardly change upon the introduction of copper and magnesium by ion exchange. [ABSTRACT FROM AUTHOR]

Hierarchical zeolites are highly‐desired catalysts in the petrochemical industry due to their shorter diffusion length, faster diffusion rate, and better accessibility to active acid sites compared with conventional zeolites. Herein, we report a simple amino‐acid‐assisted method to synthesize urchin‐like hollow hierarchical FER zeolites with abundant mesopores and macroporous inner cavities. An amino acid (i. e. L‐lysine) is used to facilitate the agglomeration of primary gel nanoparticles. The preferential nucleation and crystal growth at the external surfaces together with the lagged crystallization of the inner core of the agglomerates results in the formation of hollow inner cavities after the exhaustion of interior materials. Thanks to the unique hierarchical structure and more accessible acid sites, the hollow hierarchical FER zeolite exhibits improved catalytic performance over the conventional one in the skeletal isomerization of 1‐butene to isobutene. [ABSTRACT FROM AUTHOR]

BACKGROUND: Grand efforts have been recently devoted to the development of catalysts based on the excellent performance of Cu‐ and Fe‐dependent enzymes in methanotrophic bacteria for the partial oxidation of methane to methanol under ambient conditions. As a continuation of the study on the stepwise manner for this conversion over zeolite‐based catalysts, in this work, the effects of zeolite topology and activation temperature on the catalytic performance of Cu‐ and Fe‐containing zeolites were investigated. RESULTS: Cu species exchanged in the medium‐pore zeolites (mordenite, ZSM‐5, and ferrierite) afforded better methanol production, while large‐pore zeolites (zeolite β and zeolite γ) were inappropriate to accommodate active Cu sites. Notably, Cu/silicalite‐1 containing CuO species was also reactive to methane after the activation in O2, yielding a minor methanol amount. Furthermore, the activity of Fe/mordenite towards the methanol in the O2‐assisted procedure was reported for the first time but with a much lower yield as compared to that of Cu/mordenite. The methanol yield over Cu/mordenite increased with the activation temperature because increasing the activation temperature favored the Cu‐exchange degree with a higher priority at the side pockets as compared to the main channels of mordenite, as evidenced from infrared analysis. CONCLUSION: The selective oxidation of methane to methanol by O2 via a stepwise manner can be obtained over both ion‐exchanged Cu species and well‐dispersed CuO nanoparticles with better activity being recorded for the former. The activity of Cu‐exchanged zeolites was considerably dependent on the zeolite topology and the charge‐balancing position of the Cu2+ cations. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Methyl acetate (MA) has a wide range of applications as an important industrial chemical. Traditional MOR zeolite for carbonylation of DME to MA accumulated carbon easily because of a 12-membered ring (12 MR) channel. In this work, we innovatively developed the method of recrystallization ferrierite (FER) zeolite using special chelating ligand sodium oleate which can affect ions other than alkali metals. The characterization results of N2 adsorption, transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR) show that hydrothermal recrystallization of ferrierite using sodium oleate resulted in a higher Si/Al ratio, a bigger specific surface area and a larger number of Brønsted acid sites in the eight MR channels, which was more efficient in the reaction of carbonylation of dimethyl ether than ordinary alkali treatment. [ABSTRACT FROM AUTHOR]

Various ferrierite zeolites were investigated as catalysts for the dimethyl ether (DME)-to-olefin (DTO) reactions to efficiently synthesize n-butene, such as 1-butene, trans-2-butene, and cis-2-butene except for iso-butene using a fixed-bed flow reactor. Twenty P-loaded ferrierite zeolites with different structural parameters and acidic properties were prepared by the impregnation method by varying the P content and the temperature of air calcination as a pretreatment. The zeolites were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, and NH3 temperature-programmed desorption (NH3-TPD). Micropore surface area, external surface area, total pore volume, micropore volume, and weak and strong acid sites affected the DTO reaction behavior. A high n-butene yield (31.2 C-mol%) was observed, which is higher than the previously reported maximum yield (27.6 C-mol%). Multiple regression analysis showed that micropore surface area and strong acid sites had a high correlation with n-butene yield. Based on our findings, we explained the reaction mechanism for selective n-butene synthesis except for iso-butene in the DTO reaction by the dual cycle model. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction by methanol (Methanol-SCR) is a promising technology for removing NOx from the flue gas with high concentration of sulfur. Ferrierite (FER) zeolite has been reported as a good candidate catalyst for Methanol-SCR. Herein, the effects of the synthesis conditions on the properties of FER zeolite as Methanol-SCR catalysts have been investigated by multiple characterization technologies. It was found that FER zeolite synthesized at the temperature of 160 ~ 170 °C with pyrrolidine as SDA, aluminum sulfate as aluminum source, as well as liquid sodium silicate as silicon source exhibited the best deNOx activity for Methanol-SCR reaction. Cyclohexylamine can be used to partially replace pyrrolidine to reduce the cost of SDA, while too much of cyclohexylamine would lead to the crystallization of MOR zeolite impurities. Regulating the alkalinity of the synthesis gel by the addition of H2SO4 is an effective method for the crystallization of FER zeolite with higher SiO2/Al2O3 ratio (SAR), which exhibits an improved hydrothermal stability for Methanol-SCR (R to R2-4). [ABSTRACT FROM AUTHOR]

[Display omitted] • Butene isomerization over ferrierite requires specific types of coke deposits as active sites. • Residual organic structure direction agent (OSDA) acts as a precursor for coke-mediated reactivity. • Trace amounts of OSDA block strong acid sites preventing undesirable side reactions. • Increased accessibility of pore-mouths extends catalyst lifetime by more than two-fold. This work examines how acid site concentration (FT-IR) and strength (NH 3 -TPD) as well as pore mouth accessibility modulate the activity of the microporous zeolite ferrierite (H-FER) during the skeletal isomerization of 1-butene to iso -butene. Restricting the accessibility of catalyst pores and strong acid sites is achieved by selective oxidation of residual organic structure directing agent (OSDA) through precise control of calcination conditions. Because this reaction is mediated by catalytically active carbonaceous deposits, residual OSDA affects their formation. This work demonstrates that small amounts of residual OSDA (∼ 0.2 wt%) are beneficial to the reaction under industrially relevant reaction conditions in three ways. Selective poisoning of strong BAS with OSDA nearly halves the amount of dimerization and cracking byproducts and improves catalyst lifetime. Simultaneously, carbonaceous fragments of the OSDA act as coke precursors and help shorten the startup time. Hence, catalyst lifetime may be significantly improved through both optimal pretreatment conditions and by designing catalysts with an increased number of accessible pore mouths. [ABSTRACT FROM AUTHOR]

Ferrierite zeolite (FER) was synthesized under microwave conditions while varying the microwave exposure time from 6 to 12 h. For comparison, commercial FER and a FER zeolite synthesized by the conventional hydrothermal synthesis (72 h) were studied. The structure, texture, and acidic properties of the samples were investigated by XRD, low-temperature N 2 adsorption, ICP-AES, SEM, and DRIFT spectroscopy using adsorption of CO, CD 3 CN and pyridine as probe molecules. The catalytic characteristics of the obtained zeolites were studied in the cyclocondensation reaction of 1,2-phenylenediamine and acetone to produce 1,5-benzodiazepine. The activity of the zeolites in this reaction was found to increase with increasing microwave exposure time. The FER-MW sample synthesized in 12 h showed the best results. [Display omitted] • The zeolite with FER structure was synthesized by microwave-assisted (MW) method. • The synthesis time of FER zeolite was reduced to 6–12 h. • The acidic properties of the obtained FER depend on the MW synthesis time. • MW synthesis time affects the catalytic performance of FER. [ABSTRACT FROM AUTHOR]

In this research, the phosphotungstic acid (PTA) was impregnated on natural zeolites of clinoptilolite (Clin), mordenite (Mord), ferrierite (Ferr), and natrolite (Nat) and was characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX. The synthesized heterogeneous nanocomposites were used for oxidative desulfurization of dibenzothiophene (DBT). Among samples, PTA-Ferr has removed the most amount of DBT (82.02%) from model fuel and PTA-Nat, PTA-Clin, and PTA-Mord indicated 56.00%, 73.62%, and 67.05% removal of initial DBT, respectively. PTA-Ferr had a high surface area of 293.6 m2/g, agglomeration-free particles with an average size of 10.2 nm. To study the effect of operating parameters such as reaction time, reaction temperature and DBT concentration on the ODS activity of PTA-Ferr, a central composite design (CCD) was used. Optimized conditions for the highest DBT removal (94.39%) were obtained at a reaction time of 55 min, the temperature of 60 °C and a DBT concentration of 250 ppm. [ABSTRACT FROM AUTHOR]

Wellbore-plugging materials are threatened by challenging plugging and abandonment (P&A) conditions. Hence, the integrity and resilience of these materials and their ability to provide sufficient zonal isolation in the long-term are unknown. The present work focuses on investigating the potential to use zeolites as novel additives to the commonly used Class-H cement. Using four different zeolite–cement mixtures (0%, 5%, 15% and 30%, by weight of cement) where samples were cast as cylinders and cured at 90 °C and 95% relative humidity, the unconfined compressive strength (UCS) testing showed a 41% increase with the 5% ferrierite addition to the Class-H cement in comparison to neat Class-H cement. For triaxial compression tests at 90 °C, the highest strength achieved by the 5% ferrierite-added formulations was 68.8 MPa in comparison to 62.9 MPa for the neat Class-H cement. The 5% ferrierite formulation also showed the lowest permeability, 13.54 μD, which is in comparison to 49.53 μD for the neat Class-H cement. The overall results show that the 5% ferrierite addition is the most effective at improving the mechanical and petrophysical properties based on a water/cement ratio of 0.38 when tested after 28 days of curing in 95% relative humidity and 90 °C. Our results not only demonstrate that zeolite is a promising cement additive that could improve the long-term strength and petrophysical properties of cement formulations, but also provide a proposed optimal formulation that could be next utilized in a field trial. [ABSTRACT FROM AUTHOR]

[Display omitted] • NaOH treatment enhances CH 3 O· groups migration from iron to silicon sites. • Diffusion and desorption of products on Fe-FER are promoted following alkaline treatment. • Stability of active oxygen species on Fe-FER can be controlled by NaOH treatment. The effect of desilication on the physic-chemical properties of ferrierite zeolite was investigated using spectroscopic and solid characterisation techniques including N 2 -adsorption, XRD, SEM, H 2 -TPR, NH 3 -TPD and in situ FTIR. Stability of active oxygen species formed from N 2 O over the Fe-FER catalysts and the catalytic activity for direct conversion of methane to value-added products at temperatures between 300 °C and 400 °C were studied. Ferrierite zeolites, pre-treated with 0.1 M, 0.2 M and 0.3 M NaOH solutions preserved the crystal structure of the ferrierite zeolite but their textural properties were significantly modified, leading to an increase in mesopore area and creating a greater concentration of terminal Si-OH groups, concomitant with increase in the amount of extra-framework Al and reduction in the number of bridging Si-OH-Al species. Batch-mode catalytic reaction studies of methane with N 2 O conducted in an in situ FTIR cell demonstrate that the methoxy groups formed on extraframework iron sites followed by the migration of these species to silicon defect sites, which resulted in a decline in the intensity of terminal Si-OH groups bands in the IR spectra. N 2 O-TPD experiments confirm that N 2 O is converted to N 2 , O 2 and NO over Fe-FER catalysts at 350 °C. The decline in the desorption temperature of these products observed over Fe-FER catalysts treated with alkaline solution is consistent with a significant increase in the mesopore surface area from 28.3 m2/g to 102.4 m2/g. The peak areas of desorbed O 2 and NO were estimated, and the different ratios of O 2 /NO observed on these catalysts appears to be related to the difference stabilities of surface oxygen species. Studies under continuous reaction conditions demonstrate that, at a similar level of methane conversion (ca. 2.8 %), Fe-FER catalysts prepared with the moderately alkaline solution (0.2 M NaOH) results the highest yield of methanol, dimethyl ether and formaldehyde. It is asserted that this enhanced selectivity is the result of the comparatively high concentrations of terminal silanol groups, Brønsted-acid sites, stability of active oxygen species and mesopore volume. [ABSTRACT FROM AUTHOR]

The direct hydrogenation of CO2 into dimethyl-ether (DME) has been studied in the presence of ferrierite-based CuZnZr hybrid catalysts. The samples were synthetized with three different techniques and two oxides/zeolite mass ratios. All the samples (calcined and spent) were properly characterized with different physico-chemical techniques for determining the textural and morphological nature of the catalytic surface. The experimental campaign was carried out in a fixed bed reactor at 2.5 MPa and stoichiometric H2/CO2 molar ratio, by varying both the reaction temperature (200–300 °C) and the spatial velocity (6.7–20.0 NL∙gcat−1∙h−1). Activity tests evidenced a superior activity of catalysts at a higher oxides/zeolite weight ratio, with a maximum DME yield as high as 4.5% (58.9 mgDME∙gcat−1∙h−1) exhibited by the sample prepared by gel-oxalate coprecipitation. At lower oxide/zeolite mass ratios, the catalysts prepared by impregnation and coprecipitation exhibited comparable DME productivity, whereas the physically mixed sample showed a high activity in CO2 hydrogenation but a low selectivity toward methanol and DME, ascribed to a minor synergy between the metal-oxide sites and the acid sites of the zeolite. Durability tests highlighted a progressive loss in activity with time on stream, mainly associated to the detrimental modifications under the adopted experimental conditions. [ABSTRACT FROM AUTHOR]

In this study, 1 wt% platinum (Pt) nanoparticles were incorporated into five types of zeolites (HY, Beta, mordenite, ZSM-5, and ferrierite) with an impregnation technique. The synthesis strategy included the use of water as a solvent for the applied Pt source. Moreover, the incorporation process was performed at ambient conditions followed by calcination at 450 °C. The five prepared materials were characterized by different physical and chemical characterization techniques and the obtained results confirmed the formation of Pt nanoparticles with an average size of 5–10 nm. The catalytic performance of the prepared materials was evaluated in the hydrogenation of cyclohexene under a solvent-free system at room temperature. Pt nanoparticles supported on ZSM-5 zeolite exhibited the best catalytic performance. Moreover, the optimization of operational conditions such as temperature, pressure, and catalyst amount was investigated and the obtained results showed the possibility to convert 100% of cyclohexene within 35 min over Pt-ZSM-5. Finally, the reusability of the Pt-ZSM-5 catalyst was investigated in four consecutive runs without treatment and the obtained results showed a negligible activity loss. [ABSTRACT FROM AUTHOR]

In this work, magnetic mesoporous silica-alumina composites (MSA) containing three metal oxides(MSA/MO) with different molar ratio of Si to Al (0.5, 1 and 2) were synthesized. The efficiency of prepared catalysts was compared with modified natural zeolite (ferrierite) in the multicomponent synthesis of indeno[1,2-b]indole-9,10-diones. Immobilization of ZnO, CuO and NiO on magnetic composites increased their Lewis acidic sites and improved their catalytic activity. Also magnetic property of designed catalysts enhanced their capability and easy separation. Among the mentioned composites, the catalyst with the molar ratio of S/A = 2 show the best efficiency in the synthesis of indeno[1,2-b]indole-9,10-diones under thermal conditions and water as green solvent. FT-IR, XRD, FE-SEM, EDX, elemental mapping, BET and VSM techniques were used to characterize the prepared composites. The synthesized products were obtained in high to excellent yields and their structures were confirmed by 1HNMR, 13CNMR and FT-IR spectroscopy. [ABSTRACT FROM AUTHOR]

Two steps of dimethyl ether (DME) synthesis from CO 2 and H 2 in a batch reactor were studied, including CO 2 hydrogenation to methanol through ethanol-assisted method and methanol dehydration to DME. Additions of 10 wt% ZrO 2 , Al 2 O 3 and ZrO 2 –Al 2 O 3 into Cu/ZnO were investigated in low-temperature methanol synthesis using ethanol as catalytic solvent. Suitable zeolite (ZSM-5 and ferrierite) for methanol dehydration was also determined. Ethanol-assisted method offered high methanol yield and Cu/ZnO/ZrO 2 catalyst provided the highest CO 2 conversion (82.1%) and methanol yield (60.8%) at 150 °C and 50 bar since ZrO 2 decreased CuO crystallite sizes and increased surface areas of the catalyst. For methanol dehydration to DME, zeolite's strong acidity related to DME formation. The Cu/ZnO/ZrO 2 - Ferrierite provided the highest DME productivity at 0.44 mmol DME /g cat. In addition, DME synthesis from CO 2 and H 2 through ethanol-assisted methanol synthesis and methanol dehydration can be a potential method to simultaneously produce DME and ethylene. Under the operating conditions, ethylene was produced as a valued by-product of 5.65 mmol Ethylene /g cat from dehydration of ethanol. In this study, rather high methanol yield was obtained from ethanol-assisted method. However, DME yield can be further improved by increasing synthesis temperature. [Display omitted] • Two steps of DME synthesis from CO 2 and H 2 in a batch reactor were investigated. • Ethanol-assisted method with Cu/ZnO/ZrO 2 provided highest methanol yield (60.8%). • Ferrierite provided highest methanol dehydration to DME due to its strong acidity. • DME and ethylene can be simultaneously produced in this system. [ABSTRACT FROM AUTHOR]

A swollen ferrierite structure (denoted as ECNU‐35P) was directly synthesized with a commercially available surfactant of decamethonium hydroxide as bifunctional organic structure‐directing agent (OSDA). ECNU‐35P, with elastic long‐chain surfactant intercalating the neighboring FER layers, had a much wider interlayer spacing than previously reported FER‐type layered precursors of PLS‐3 and PREFER. The phase delamination of ECNU‐35P was readily realized without additional swelling process that is destructive to zeolite frameworks. The non‐corrosive delaminated derivative (DECNU‐35) was composed of the FER nanosheets with 4 nm‐thickness. With large external surface area, abundant mesopores and moderate acidity, Pd/DECNU‐35 served as highly active and robust catalysts in the reductive etherification of biomass furfural, providing a high yield of 74 % for the biofuel of furfuryl ethyl ether. [ABSTRACT FROM AUTHOR]

[Display omitted] 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 [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovative preparation of finned-FER zeolites via a novel seed-mediated method using microwave heating; • Friedel-Crafts alkylation reaction with triphenylphosphine to assess the performance of the synthesized zeolites; • Demonstrated high efficiency in the isomerization of methyl oleate, achieving over 70% yield of branched isomers at 89% conversion; • Research offers advancements in finned-FER zeolite synthesis, with implications for improved catalytic efficiency and biodiesel sustainability. The skeletal isomerization of fatty acid methyl esters (FAME) is vital for producing branched-chain esters and is a great tool to improve the cold flow properties of biodiesel. Ferrierite (H-FER) zeolite is an effective catalyst for facilitating this reaction; however, its efficiency can be limited by site accessibility and pore structure. Thus, our research developed a novel method for producing finned-FER zeolites by a seed-mediated approach that applies microwave heating with H-FER as seeds. The main focus was to examine how varying synthesis conditions, particularly microwave heating time, influenced the physical and chemical properties of the produced zeolites; we showed that the optimized condition was achieved with 6 h of microwave heating, revealing well-defined finned crystals and improved characteristics. Finally, the study evaluated the catalytic performance of these finned-FER zeolites. The Friedel-Crafts alkylation reaction, serving as a model reaction, was employed to assess the performance of the materials. We also accessed the performance of these materials in the same reaction in the presence of triphenylphosphine, offering a deeper understanding of the real active sites and their accessibility. Furthermore, the isomerization reactions of methyl oleate were explored to evaluate the practical applicability of the synthesized zeolites. The results revealed that branched isomers exceeding 70 % yield were achieved at 89 % conversion for the best catalyst at a temperature of 250 °C and 20 bar of H 2 for 6 h. Thus, this research proposes a more efficient method for synthesizing finned-FER zeolites and systematically analyzes their characteristics, highlighting potential improvements in catalytic efficiency and sustainability. [ABSTRACT FROM AUTHOR]

• The FER with nano-sized fins was successfully prepared by a secondary growth method. • The finned FER shows more BASs and shorter diffusion pathway. • Both increased BASs and improved diffusion properties contribute to the enhanced DME carbonylation activity. The carbonylation of dimethyl ether (DME) to produce methyl acetate (MA) has a promising prospect in industry. FER zeolites have high MA selectivity and considerable stability but suffer from low activity due to diffusion limitation. Enhancing the diffusion properties of FER zeolites can improve their competitiveness in the DME carbonylation. This study proposed the synthesis of finned FER zeolites with low Si/Al ratio by a secondary growth method. Based on NH 3 -TPD and FTIR, the amount and distribution of acid sites in FER with fins were determined. Combining the normalized MA formation rates on the BASs in 8-MR and diffusion kinetic studies of DME, the influence of diffusion limitation was quantitatively discussed. The results showed that the acidity and diffusion properties were significantly improved on the finned FER, which boosted the DME conversion. This work illustrated the importance of the acidity and diffusion properties in FER catalyzed DME carbonylation. It inspires the rational design of zeolite catalysts by constructing morphology and optimizing compositions. [ABSTRACT FROM AUTHOR]

[Display omitted] • ITQ-6-based catalysts showed smaller Ni NP's and H 2 uptake than the FER-based ones. • Al-containing catalysts exhibited higher Ni dispersion and OH group concentration. • ITQ-6-based catalysts showed higher CO 2 conversion and CH 4 selectivity (>90 %). • E a calculations indicated that the associative mechanism is favored in ITQ-6 catalysts. • 15Ni/ITQ-6 (Si/Al = 30) exhibited high CO 2 conversion and CH 4 selectivity (79 % and 98 %, respectively, at 400 °C). Ni-based catalysts supported on delaminated ITQ-6 zeolite with different Si/Al ratios, 30 and ∞, were tested in the methanation of CO 2 and CO. ITQ-6 supports exhibited high surface areas (> 590 m2/g), and the catalysts based on them presented elevated CO 2 and CO conversion values, turnover frequencies (TOF), and CH 4 selectivity (> 90 %). Comparing the ITQ-6 catalyst and its precursor ferrierite (FER)-based catalyst, H 2 -chemisorption results confirmed higher metallic dispersion for the former, which resulted in improved H 2 uptake and efficient interaction of reaction intermediates via the associative pathway. Combined kinetic studies indicated that their higher available metallic surface contributed to lower apparent activation energies towards CH 4 formation, accounting for the higher selectivity values. A 15 wt% Ni-based catalyst supported on ITQ-6 zeolite (Si/Al = 30) exhibited catalytic results (X CO2 = 79 % y S CH4 = 98 %) comparable or even superior to some of the best zeolite-based catalysts reported so far. [ABSTRACT FROM AUTHOR]

Nowadays, fibrous minerals pose as significant health hazards to humans, and exposure to these fibers can lead to the development of severe pulmonary diseases. This work investigated the morphology, crystal structure, chemistry, and surface activity of fibrous ferrierite recently found in northern Italy through an integrated approach using scanning electron microscopy–energy dispersive spectroscopy, electron microprobe, inductively coupled plasma atomic emission spectrometry, X-ray powder diffraction, and electron paramagnetic resonance. Our results show that a notable amount of ferrierite fibers are breathable (average length ~22 µm, average diameter 0.9 µm, diameter-length ratio >> 1:3) and able to reach the alveolar space (average Dae value 2.5 μm). The prevailing extra-framework cations are in the Mg > (Ca ≈ K) relationship, R is from 0.81 to 0.83, and the Si/Al ratio is high (4.2–4.8). The bond distances suggest the occurrence of some degree of Si,Al ordering, with Al showing a site-specific occupation preference T1 > T2 > T3 > T4. Ferrierite fibers show high amounts of adsorbed EPR probes, suggesting a high ability to adsorb and interact with related chemicals. According to these results, fibrous ferrierite can be considered a potential health hazard, and a precautionary approach should be applied when this material is handled. Future in vitro and in vivo tests are necessary to provide further experimental confirmation of the outcome of this work. [ABSTRACT FROM AUTHOR]

The review analyzes the specific features of methyl acetate synthesis by dimethyl ether carbonylation in the presence of zeolite catalysts. The structural characteristics of zeolites, in particular, mordenite and ferrierite, that affect carbonylation are discussed. The bridging hydroxyl groups (Al–OH–Si) of zeolites function as Brønsted acid sites and interact with dimethyl ether. The carbonylation reaction is characterized by an induction period, during which dimethyl ether molecules interact with Brønsted acid sites to form methoxy groups. The incorporation of CO into the methoxy group leads to the formation of an acetyl intermediate. Methyl acetate is formed due to the interaction between a dimethyl ether molecule and an acetyl intermediate. The reaction is facilitated by the confinement effect characteristic of small zeolite pores, in particular, eight-membered pockets of mordenite. Methyl acetate is synthesized at moderate temperatures (about 200°C) in a CO–dimethyl ether mixture at a high selectivity and a significant dimethyl ether conversion. The occurrence of hydrocarbon formation side reactions, along with the methyl acetate synthesis target reaction, is observed; the side reactions decrease the on-stream stability of the catalyst. In the case of mordenite, these reactions are attributed to the sites present in the twelve-membered channels. The on-stream stability of the catalysts can be increased by using special techniques for neutralizing the deactivating sites of the zeolite. The effect can be achieved by pyridine adsorption or ion exchange of the respective protons of the mordenite structure for organic or metal cations. The introduction of zinc ions and, additionally, copper ions significantly inhibits the activity of the mordenite sites on which the side reactions occur. A new area of research is the use of multifunctional catalysts that mediate methyl acetate synthesis directly from synthesis gas. [ABSTRACT FROM AUTHOR]

Designing zeolite catalysts with improved mass transport properties is crucial for restrictive networks of either one‐ or two‐dimensional pore topologies. Here, we demonstrate the synthesis of finned ferrierite (FER), a commercial zeolite with two‐dimensional pores, where protrusions on crystal surfaces behave as pseudo nanoparticles. Catalytic tests of 1‐butene isomerization reveal a 3‐fold enhancement of catalyst lifetime and an increase of 12 % selectivity to isobutene for finned samples compared to corresponding seeds. Electron tomography was used to confirm the identical crystallographic registry of fins and seeds. Time‐resolved titration of Brønsted acid sites confirmed the improved mass transport properties of finned ferrierite compared to conventional analogues. These findings highlight the advantages of introducing fins through facile and tunable post‐synthesis modification to impart material properties that are otherwise unattainable by conventional synthesis methods. [ABSTRACT FROM AUTHOR]

The development of heterogeneous catalysts for light olefin production via a catalytic cracking has been crucially important due to the high demand of related products in industrial applications. Herein, we report the structural analysis of a germanium‐substituted hierarchical ferrierite zeolite obtained by one‐pot synthesis. This is the first report on an investigation of the synergistic effect of hierarchical structures and the one‐pot Ge‐substitution in a ferrierite framework on the catalytic cracking mechanism. Our findings exhibit that the existence of germanium in a hierarchical ferrierite framework can indeed reduce the Brønsted acid strength, facilitating a catalytic reaction with high light olefin selectivity (63 %) due to the elimination of side reactions, such as dimerization and aromatization, confirmed by in‐situ DRIFTS and DFT studies. This opens up the perspective of the development of metal substitution in an interconnected 8‐ and 10‐pore framework with hierarchical structures on the catalytic behaviors of light olefin production. [ABSTRACT FROM AUTHOR]

Pd‐loaded FER and SSZ‐13 zeolites as low‐temperature passive NOx adsorbers (PNA) are compared under practical conditions. Vehicle cold start exposes the material to CO under a range of concentrations, necessitating a systematic exploration of the effect of CO on the performance of isolated Pd ions in PNA. The NO release temperature of both adsorbers decreases gradually with an increase in CO concentration from a few hundred to a few thousand ppm. This beneficial effect results from local nano‐"hot spot" formation during CO oxidation. Dissimilar to Pd/SSZ‐13, increasing the CO concentration above ≈1000 ppm improves the NOx storage significantly for Pd/FER, which was attributed to the presence of Pd ions in FER sites that are shielded from NOx. CO mobilizes this Pd atom to the NOx accessible position where it becomes active for PNA. This behavior explains the very high resistance of Pd/FER to hydrothermal aging: Pd/FER materials survive hydrothermal aging at 800 °C in 10 % H2O vapor for 16 hours with no deterioration in NOx uptake/release behavior. Thus, by allocating Pd ions to the specific microporous pockets in FER, we have produced (hydro)thermally stable and active PNA materials. [ABSTRACT FROM AUTHOR]

Tandemly coupled gas-phase CO 2 hydrogenation reaction to dimethyl ether (DME) with its successive carbonylation (CO insertion) for one-step methyl acetate (MA) synthesis was investigated on newly designed SiO 2 -encapsulated Cu-ZnO nanoparticles (CZ@Si) hybridized with nano-sized Ferrierite (NFER) zeolite. The core-shell-structured CZ@Si with thermally stabilized Cu-ZnO nanoparticles having stronger Cu-O-Si interfaces was crucial to form an optimal CO/DME ratio, which was found to be a key step to switch the reaction pathway from methanol-mediate hydrocarbon formation route to carbonylation route to selectively synthesize oxygenates by CO 2 hydrogenation-initiated tandemly coupled reaction. The formed methanol intermediate was further reacted to form DME by methanol dehydration, and the rates of surface methoxy formation and CO insertion to form acetyl intermediate were enhanced with the increased Brønsted acid sites in 8-membered ring channels on the NFER with higher MA selectivity of ∼50% through novel tandem reaction for efficient CO 2 utilization. [Display omitted] • Tandemly coupled CO 2 hydrogenation to direct methyl acetate synthesis was investigated. • SiO 2 -encapsulated Cu-ZnO nanoparticles was well hybridized with nano-sized ferrierite. • CO 2 hydrogenation-initiated DME carbonylation revealed higher MA selectivity of ∼50%. [ABSTRACT FROM AUTHOR]

Geopolymers can be transformed into zeolites under certain synthesis conditions. However, zeolite formation is not frequently reported in KOH-activated geopolymers. This study attempted to explore zeolite synthesis through geopolymerization for a curing time of 24 h using mixed NaOH/KOH alkaline solution as an activator, and then applying the geopolymer-supported zeolites to immobilize Cd(II) in paddy soil. The K2O/M2O--H2O/SiO2 and K2O/M2O--OH--/SiO2 binary zeolite crystallization phase diagrams were obtained. Zeolite A, faujasite and sodalite formed at lower K2O/M2O molar ratios (0-0.2), ferrierite formation was favoured at a K2O/M2O molar ratio of 0.2-0.4 and zeolite K-I and zeolite F-K (both K-zeolites) were observed at a K2O/M2O molar ratio of 0.6. The geopolymer-supported zeolites had micropores and mesopores and specific surface area values of 44.2-74.8m² g-1. The material displayed a considerable Cd(II) immobilization efficiency (55.6-58.7% at 4-6 wt.% addition of zeolite). [ABSTRACT FROM AUTHOR]

[Display omitted] • DME synthesis by CO 2 hydrogenation was optimized on CZA/FER (Si/Al ratio of 12). • Smaller Cu nanoparticles decorated with ZnO moiety on CZA enlarged hydrophobicity. • Hydrophobic surfaces were related with the contents of smaller ZnO moiety on CZA. • Competitive adsorption of water was suppressed on the hydrophobic CZA/FER surfaces. The maximum production rate of dimethyl ether (DME) through direct CO 2 (or CO) hydrogenations on the bifunctional Cu-ZnO-Al 2 O 3 hybridized with highly crystalline ferrierite (FER) zeolite (CZA/FER) was observed at an optimal Si/Al molar ratio of ∼12 (CZA/FER(12)) due to its larger metallic surface area of Cu nanoparticles and relatively higher hydrophobic surface natures. The smaller size of metallic Cu nanoparticles in the larger Cu-ZnO-Al 2 O 3 matrices decorated with smaller ZnO moiety effectively increased the hydrophobic surfaces of the CZA/FER(12), which further preserved the larger number of acidic sites on the FER surface. The phenomena also caused less aggregations of Cu nanoparticles by their stronger interactions in the Cu-ZnO-Al 2 O 3 matrices. The higher CO 2 (and CO) conversion and DME productivity of 4.53 mmol/(g cat h with lower CO formation rate of 0.90 mmol/(g cat h on the CZA/FER(12) were attributed to the stable preservations of the strongly interacted smaller Cu nanoparticles even under water excess environment by easily desorbing water molecules with its suppressed competitive adsorptions on the hydrophobic CZA/FER(12) surfaces. [ABSTRACT FROM AUTHOR]

Splitting dioxygen to yield highly active oxygen species attracts enormous attention due to its potential in direct oxidation reactions, mainly in transformation of methane into valuable products. Distant binuclear cationic Fe(II) centers in Fe‐ferrierite have recently been shown to be active in splitting dioxygen at room temperature to form very active oxygen species able to oxidize methane to methanol at room temperature as well. Computational models of the distant binuclear transition metal cationic sites (Co(II), Mn(II), and Fe(II)) stabilized in the ferrierite matrix were investigated by periodic density‐functional theory calculations including molecular dynamics simulations. The results reveal that the M(II) cations capable of the M(II) → M(IV) redox cycle with the M...M distance of ca 7.4 Å stabilized in two adjacent β sites of ferrierite can split dioxygen. Our study opens the possibility of developing tunable zeolite‐based systems for the activation of dioxygen employed for direct oxidations. [ABSTRACT FROM AUTHOR]

Here we demonstrate for the first time the splitting of dioxygen at RT over distant binuclear transition metal (M = Ni, Mn, and Co) centers stabilized in ferrierite zeolite. Cleaved dioxygen directly oxidized methane to methanol, which can be released without the aid of an effluent to the gas phase at RT. [ABSTRACT FROM AUTHOR]

[Display omitted] • Evidence for C C protonation as prevailing mechanism for alkane cracking. • Identification of a new concerted reaction pathway for propane cracking. • Intrinsic barriers for propane cracking are nearly constant with pore size variation. • CCSD(T) quality potential energy surfaces indispensable for mechanism discrimination. A hybrid QM:QM method (MP2:(PBE+D2) + ΔCCSD(T)) is employed that reaches chemical accuracy (±4 kJ mol−1) for periodic systems. Three mechanisms are considered and evidence is produced that cracking proceeds via protonation of a C C bond at the Brønsted acid site. For H-FER, H-MFI, and H-CHA, the deviations between predictions (uncertainty ± 4 kJ mol−1) and experiment (error ± 5 kJ mol−1) are between −3 and +8 kJ mol−1. The predicted apparent enthalpy barriers for H-FER, H-MFI, H-CHA, and H-FAU at 650 K are 153, 153, 160, and 182 kJ mol−1, respectively. Their variation with the pore size is dominated by the adsorption enthalpies (−55, −47, −40, and −29 kJ mol−1, respectively), whereas the intrinsic enthalpy barriers vary within a narrow range of 10 kJ mol−1 only. Routine PBE+D2 calculations show large errors, −16 to −20 and −40 to −60 kJ mol−1 for adsorption enthalpies and enthalpy barriers, respectively. [ABSTRACT FROM AUTHOR]

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• Ferrierite-type zeolite was dealuminated by solutions of hydrochloric acid. • The samples were highly crystalline and contained Brønsted and Lewis acid sites. • Initial reaction rate and turnover frequency of α-pinene at 348–363 K were estimated. • Selectivity to camphene and limonene was in the range of 77–98.9 %. 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 T B sites located in the main channels and T A 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 T B and up to 19-% from T A sites. The amount and strength of Brønsted 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 %. [ABSTRACT FROM AUTHOR]

Zeolites of type ferrierite are exploited as a host system for monitoring the evolution of guest concentration (methanol) in nanoporous host materials upon adsorption. Additional transport resistances at the crystal surface have been removed so that uptake is exclusively controlled by the diffusion resistance of the pore space. Since the crystal shape deviates from a simple parallelepiped, the primary imaging data do not immediately reflect true local concentrations. A simple algorithm is developed which overcomes this complication. The determined transient concentration profiles ideally comply with the requirements for the application of the Boltzmann-Matano integration method for determining diffusivities. The resulting diffusivities (along the direction of the '10-ring channels') are found to exceed those along the 8-ring channels by three orders of magnitude. [ABSTRACT FROM AUTHOR]

This study investigated for the first time the synthesis of ferrierite zeolite through the vapor-phase transport method using the cationic polymer Luviquat as a mesopores-generating agent, followed by desilication treatment. The effect of ferrierite's textural and acid properties was then evaluated in the catalytic cracking of ultra-high molecular weight polyethylene (UHMWPE). The synthesized zeolites showed a crystallinity of 91%–100% and similar Si/Al ratios. After the desilication, there was a decrease in these values along with an increase in acidity, attributable to the extraction of structural silicon. The strong interaction between the polymer and the zeolite precursor during the self-assembly process led to the formation of intracrystalline mesoporosity. However, an internal diffusion limit and/or steric hindrance hinders the complete incorporation of the polymer into the ferrierite structure, especially at high polymer concentrations. Thus, the optimal composition was 40% Luviquat, which resulted in twice the volume of mesopores compared to the sample prepared without the polymer. The desilication of the samples synthesized with the Luviquat led to a substantial increase in mesoporosity, ranging from 67% to 183%, relative to microporous ferrierite. The introduction of mesoporosity and the modification of acid properties in ferrierite contributed to a reduction in the temperature for the cracking of UHMWPE, between 66 and 93 °C compared to the pure polymer. However, in all cases, there was an increase in the average apparent activation energy in relation to desilicated microporous ferrierite zeolite, possibly due to changes in product distribution. [Display omitted] • Hierarchical FER was obtained using the polymer Luviquat, followed by desilication. • The use Luviquat in the VPT method improved the physicochemical properties of FER. • Desilication enhanced ferrierite acidity and intracrystalline mesoporosity. • Optimal composition: 40% Luviquat, doubling mesopores volume. • Modified FER lowered UHMWPE cracking temperature, affecting product distribution. [ABSTRACT FROM AUTHOR]

FER nanosheets with preferential Al atoms sitting in T2 and T4 sites were synthesized by the addition of CTAB, resulting in improved of DME conversion, catalyst stability and STY MA in the DME carbonylation reaction. [Display omitted] • The FER nanosheets with preferential Al-sitting in T2 and T4 sites was synthesized. • The introduction of CTAB tuned the length ratio along the b -axis to c -axis of the FER crystals. • The reduced crystal size and the suitable location of acid sites enhanced DME carbonylation performance. Enriching Al atoms in T2 and T4 sites of FER zeolite is decisive for achieving high catalytic activity in the carbonylation reaction of dimethyl ether (DME). Regulating the spatial position of Al atoms in targeted framework sites remains to be a great challenge during the synthesis of FER zeolite. The FER nanosheets with preferential Al-sitting in T2 and T4 sites were successfully synthesized with the assistance of cetyltrimethylammonium bromide (CTAB). The effect of CTAB on the morphology and Al distribution has been investigated in detail. CTAB mostly adsorbed on external surface serving as growth inhibitors, which resulted in nanosheet morphology and changed the length ratio along the b -axis to c -axis of the crystals. A minor portion of CTAB located in the channels may favor the spatial Al location in T2 and T4 sites, indicated by the results from 27Al MAS NMR spectra. The FER nanosheets exhibited improved DME conversion, stability, space–time yield (STY), and lifetime compared to conventional FER in DME carbonylation reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • String-like thinner FER was prepared with two different organic structure directing agents. • Larger strong Brønsted acid sites showed a higher activity and stability for carbonylation. • Appropriate ratio of CTAB to piperidine showed the most stable DME adsorption natures. String-like thinner morphology of FER zeolite (SFER) having considerable amount of strong acidic sites was successively synthesized by using two different organic structure directing agents (OSDA) such as CTAB and piperidine, which showed larger number of active strong Brønsted acid sites with higher catalytic activity and stability for a gas-phase carbonylation of dimethyl ether (DME) to methyl acetate (MA). The effects of synthesis procedures and surface properties were verified by using surface acidic sites measurements and molecular dynamics (MD) analysis, where an appropriate molar ratio of CTAB to piperidine (∼0.5) showed the most stable DME adsorption natures with catalytic stability. The ultrathin-layers with string-like FER morphology were found to be excellent to enhance a gas-phase DME carbonylation activity with an increased stability of the FER structures, which was mainly attributed to the enhanced mass transfer rate in the string-like thinner FER micro and mesopore channels with larger strong Brønsted acid sites resulted in the suppressed depositions of coke precursors. [ABSTRACT FROM AUTHOR]

• Seed-derived ferrierite (FER) without any organic structure-directing agent (OSDA) showed a higher activity and stability. • Optimal amount of commercial FER-seed (15 wt%FER) stabilized Brønsted acidic sites. • Less formation of coke precursors was obserbed by decreasing Lewis acidic EFAL defect sites. The seed-derived ferrierite zeolite (FER) synthesized at different contents of FER seed component without using any organic structure-directing agent (OSDA) showed a higher catalytic activity and stability for a gas-phase carbonylation of dimethyl ether (DME) to methyl acetate (MA) at an optimal amount of the previously synthesized FER-seed with 15wt%. The optimal amount of FER-seed material played an important role to optimize the numbers of active Brønsted acid sites in 8-membered ring (8-MR) channels with less formation of coke precursors by decreasing defect sites through their recrystallization during the preparation step. The defected Lewis acidic extra-framework aluminum (EFAL) sites on the seed-derived FER surfaces were responsible for preferential coke depositions and for a retarded CO insertion by decreasing the rate of the gas-phase DME carbonylation reaction. [ABSTRACT FROM AUTHOR]

The ferrierite crystal structure has often been subject to discussion because of the possible lowering of symmetry from the space group Immm. It mainly occurs in nature with a fibrous crystal habit, and because of the existence of line/planar defects in the framework, texture and preferred orientation effects it has been difficult to obtain an exact crystallographic model based only on the results from powder diffraction data. Therefore, nano‐single‐crystal diffraction and tomography data have been combined in order to improve the refinement with a meaningful model. High‐quality single‐crystal data, providing reliable structural information, and tomography images have been used as input for a Rietveld refinement which took into account a phenomenological description of stacking disorder and the analytical description of the preferred orientation, by means of spherical harmonics for strong texture effects. This is one of the first examples of application of synchrotron nano‐diffraction for the structure solution of fibrous minerals of micrometre to nanometre size. The high quality of the crystals allowed collection of single‐crystal X‐ray diffraction data of up to 0.6 Å resolution, leading to an unambiguous solution and precise anisotropic refinement. Nano‐single‐crystal diffraction and phase contrast tomography data were collected at ID11 and the high‐resolution powder diffraction patterns at ID22 of the European Synchrotron Radiation Facility. This detailed crystallographic characterization provides a basis for understanding the potential of ferrierite for toxicity and carcinogenicity. [ABSTRACT FROM AUTHOR]