Short Crystallization Time Research Articles

Facile synthesis of SSZ-16 nanoaggregates with excellent performance in NH3-SCR reaction

d6r units were proved to be crucial for the synthesis of SSZ-16 zeolite with AFX topology, and FAU zeolite owning plenty of d6r units was chosen as the essential raw material for constructing AFX frameworks. In this work, SSZ-16 zeolite was directly synthesized using colloidal silica and sodium aluminate as the raw materials in short crystallization time of 5 h. The corresponding crystallization process were carefully investigated by various characterizations, demonstrating that the key to this success was the formation of d6r units built up by a large amount of s4r units which were formed with the assistance of the appropriate organic structure directing agent (OSDA) and seeds in the synthetic media. Interestingly, the products of C-SSZ-16 zeolites presented spherical shapes consisted of relatively small particles with size range from 30 to 50 nm. Moreover, after ion-exchanged with Cu ions, the Cu-C-SSZ-16 products showed excellent performance in the selective catalytic reduction of NOx with NH3 (NH3-SCR) and better hydrothermal stability than conventional Cu-SSZ-16-con samples due to slightly higher Si/Al ratio of the Cu-C-SSZ-16. Therefore, remarkable catalytic performance and the use of low-cost raw materials as well as short period of synthesis time make AFX zeolites as potential applicants in NH3-SCR field, from an industrial viewpoint.

Quantitative structural characterization of LiNbO3-SiO2 glass-ceramics by multinuclear solid-state NMR

This study presents a detailed structural analysis of the glass-to-crystal transition in the technologically important LiNbO3–SiO2 glass system, focusing on the composition 35Li2O–25Nb2O5–40SiO2 known for its exceptional second harmonic generation (SHG) response in glass-ceramics. We develop a comprehensive solid-state NMR protocol to quantify major and minor fractions of elusive nanocrystalline phases and the residual glass composition, overcoming limitations of techniques such as X-ray diffraction and Raman spectroscopy. By employing 7Li satellite transition difference spectroscopy and 93Nb magic-angle spinning (MAS) NMR, we achieve quantification of crystalline fractions down to 1%. By combining all the complementary 6Li, 7Li, 29Si, and 93Nb MAS NMR experiments, we also deduce the composition of the residual glass. Short crystallization times (up to 120 min) at 640 °C result in nanocrystalline LiNbO3, whereas crystallization for 1440 min at this temperature additionally yields two Li2Si2O5 polymorphs and Li2SiO3. 7Li spin echo and 7Li{93Nb} W-RESPDOR NMR spectroscopy indicate that LiNbO3 crystallizes in specific domains leaving behind SiO2-rich residual glassy domains. This work offers a time-efficient and versatile NMR protocol for characterizing crystalline and residual glass components in nanocrystalline glass-ceramics in the LiNbO3–SiO2 system and beyond, providing valuable insights into the crystallization process which is not possible with other techniques.

Preparation of enstatite-spinel based glass-ceramics from ferronickel slag and iron ore tailings by microwave-assisted one-step crystallization

A novel method to prepare high-quality enstatite-spinel based glass-ceramics by co-utilization of ferronickel slag (FNS) and iron ore tailings (IOT) via microwave-assisted one-step crystallization was proposed with an emphasis on the effect of IOT content on the preparation process. The thermodynamic analysis demonstrated that incorporating appropriate amounts of IOT into FNS can effectively transform olivine in FNS into enstatite. The experimental exploration revealed that the crystallization activation energy of the parent glass decreased from 564.6 kJ/mol to 351.93 kJ/mol when the IOT content increased from 30 wt% to 45 wt%. Meanwhile, the Avrami index of the parent glass increased from 3.88 to 4.81, indicating less depolymerization. In the subsequent crystallization process, with increasing content of IOT, the main phase was enstatite, accompanied by small amounts of spinel which acted as nucleation sites promoting the enstatite formation. Due to the decreased depolymerization degree that resulted in fewer nucleation sites, the average grain size of enstatite increased from 123 nm to 196 nm. By controlling crystallization of the melted mixture of 65 wt% FNS and 35 wt% IOT at 863 °C for 20 min, the resulting enstatite-spinel based glass-ceramics had excellent comprehensive properties, namely density of 3.13 g/cm3, bending strength of 153.53 MPa, Vickers microhardness of 9.22 GPa, acid resistance of 99.89%, and alkali resistance of 99.72%. With a much shorter crystallization time (1/6 of conventional one), the product obtained by microwave-assisted one-step crystallization had properties comparable to those derived from similar wastes.

Influence of metal ions (Me: Fe, Cu, Co, Ni, Mn, Cr) on direct Z-scheme photocatalysts CN/Me-BTC on the degradation efficiency of tetracycline in water environment

BackgroundThe World Health Organization (WHO) reports that antibiotic resistance contributes to approximately 700,000 deaths yearly, with estimate suggesting a rise to 10 million deaths over the next 35 years. MethodsIn this study, direct Z-scheme heterojunction photocatalysts CN/Me-BTC (CN: graphite carbon nitride, Me: metal ions, BTC: benzene-1,3,5-tricarboxylic acid) were successfully synthesized using a hydrothermal combined microwave method, eliminating the need for toxic solvents and featuring a short crystallization time and low reaction temperature. Significant findingsThe study also explores the influence of various metal ions (Fe, Ni, Co, Mn, Cr, and Cu) on the morphological, physicochemical properties, and photocatalytic efficiency of tetracycline (TC) degradation. The CN/Me-BTC photocatalysts exhibit remarkable characteristics, including high visible light absorption, high surface area, low recombination rate between electrons and holes, and fast charge transfer ability.Among the synthesized photocatalysts, CN/FeBTC stands out with the highest efficiency in TC degradation (97.18 %) and degradation rate (decay constant k = 0.0197 min−1), surpassing CN by four times. The study comprehensively investigates factors influencing the TC degradation process, including catalyst mass, pH, antibiotic concentration, participating radicals, anions, and water sources. The mechanism of the photocatalytic process is elucidated based on radical quenching experiments and electrochemical properties.

A rapid and eco-friendly approach for the synthesis of low-silica SAPO-34 with excellent MTO catalytic performance.

A rapid and eco-friendly route has been developed for the synthesis of SAPO-34 with short crystallization time (1-3 h), low silica content (as low as 6.2 wt%) and excellent methanol-to-olefin (MTO) catalytic performance by utilization of a recycled mother liquid at elevated crystallization temperature.

Synthesis of EMT/FAU-type zeolite with high crystallinity and high EMT yield

EMT/FAU-type zeolite was synthesized by hydrothermal synthesis (initial gel composition: 10SiO2: 1Al2O3: xNa2O: 0.5 18-crown-6: 140H2O; x = 2.3, 2.7, 3.1 and 3.5) using 18 crown-6 as the template. The samples were characterized via XRD, BET and SEM techniques. The results illustrated that sodium hydroxide concentration in the initial gel (or in other words equivalent of Na2O) markedly affected the type and yield of the phases formed, morphology and textural property of the synthesized zeolites. With 3.1 equivalent of Na2O in the initial gel, the SEM result showed regular hexagonal platelets (2–5 μm in diameter), implying formation of well crystalline EMT phase being confirmed by XRD results as well. However, with lower or higher addition of Na2O amorphous or fujasite phases formed, respectively. In addition, the increase of the amount of sodium hydroxide reagent enhanced the BET surface area and microporous volume of the obtained zeolites. The high yield Na-EMT zeolite (∼70 %) produced in a short crystallization time (8 d) could be easily recovered from the synthesis slurry by filtration and washing without needing high-speed centrifugation.

Boosting the low-temperature activity of fast-synthesized Cu-SAPO-18 for NH3-SCR by hydrothermal treatment

Cu-SAPO-18 catalysts attracts increasing attention in the reaction of selective catalytic reduction (SCR) of nitrogen oxides (NOx), but the catalyst synthesis process is complicated and time-consuming. Also, it is urgent to enhance the low-temperature catalytic conversion of NOx for practical applications. Herein, we reported a fast-synthesis method to prepare the Cu-SAPO-18 catalysts in 32–80 h, and the catalysts showed an excellent catalytic performance of over 80 % NO conversion at 260–480 °C. The crystalline of the catalysts was improved in short crystallization time and high crystallization temperature, accelerating the NH3-SCR reaction. The low-temperature activity of all catalysts was improved after hydrothermal treatment, and the temperature range of over 80 % NO conversion was extended to 190–515 °C for the optimized catalyst, which was due to the increasing active Cu2+ species (ZCuOH and Z2Cu, where Z represents an anionic site on the zeolite framework). The redox cycle of Cu2+/Cu+ was accelerated and more Lewis acid sites on the catalyst enhanced the NO/NH3 adsorption and activation, promoting the low-temperature catalytic activity. Furthermore, after hydrothermal treatment, part of Z2Cu species converted to ZCuOH species, which exhibited stronger NO adsorption energies (−2.06 eV) than that of Z2Cu (−1.38 eV) based on theoretical calculation. Both fresh and aged catalysts showed remarkable SO2/H2O resistance. This work reveals the effects of hydrothermal treatment on the Z2Cu and ZCuOH species, which is helpful to prepare the fast-synthesized zeolite catalysts with excellent low-temperature SCR performance.

Oxidative stability and characterization of oleogels obtained from safflower oil‐based beeswax and rice bran wax and their effect on the quality of cake samples

AbstractSafflower oil‐based oleogels were produced from beeswax and rice bran wax. Oleogels demonstrated higher oxidative stability than shortening at the cooking temperature. Peroxide values in shortening, rice bran wax oleogels, and beeswax oleogels samples were found in the range of 4.8–27.76, 13.21–20.45 and 4.30–7.72 meqO2kg−1 oil. Following oleogelation, there was no significant change in fatty acid composition of safflower oil. In addition, after baking process, the changes in the major fatty acids were not determined to be significant. Solid fat content ratios (carried out at 35°C) of rice bran wax oleogels, in beeswax oleogels and in shortening samples were defined in the range of 4.10%–7.70%, 0.80%–5.00%, and 9.61%, respectively. The highest oil binding capacity was revealed in beeswax oleogels with 99.93%–99.98%. The shortest crystallization time was determined as 3 min in oleogel containing 10% rice bran wax. Cakes consisted of oleogel were acceptable in terms of texture and sensory properties compared to cake produced with shortening. Sensory results revealed that some cakes produced with oleogels were found to be more acceptable as compared with control group samples. In this respect, oleogels produced with safflower oil‐based beeswax and rice bran wax could be used instead of commercial solid fat widely used in the cake industry.

Rapid synthesis of high-selective Al-rich beta zeolite membrane via an organic template-free route for pervaporation dehydration of water-n-butanol mixtures

The high-selective Al-rich beta zeolite membranes were rapidly fabricated on porous α-alumina supports via an organic template-free and fluoride-containing route. The growth process of Al-rich beta zeolite membrane transformed from high-silica beta seed crystals was investigated in details. With the help of NaF, the high-silica seed with a Si/Al ratio of ∼ 25 gradually dissolved into an amorphous layer, and then more AlO4 gathered on the amorphous layer and rearranged with SiO4 to form Al-rich beta crystals with a Si/Al ratio of ∼ 2.7. A continuous and compact membrane layer was obtained for a short crystallization time of 48 h by conventional heating. The synthesized Al-rich beta zeolite membrane with strong hydrophilicity was applied in the dehydration of organic solvents for the first time. The membrane exhibited a permeation flux of 2.84 kg m-2h−1 and a high separation factor of 17,900 for a 90 wt% n-BuOH/H2O mixture at 348 K. Even in a 95 wt% n-BuOH/H2O mixture, the membrane showed a high selectivity together with the water content in permeate of 99.93 wt%, indicating that the Al-rich beta zeolite membrane was a promising candidate for dehydration of organic solvents.

Synthesis of zeolite W from alkali fusion activated K‐feldspar by gel‐like‐solid phase method

AbstractZeolite W with the spindle morphology has been rapidly synthesized from alkali fusion activated K‐feldspar via gel‐like‐solid phase method after supplementing a small amount of silica‐aluminum xerogel. The effects of n(H2O)/n (SiO2), m (activation product)/m (xerogel), and crystallization time on the synthesis of zeolite W were investigated. The optimal synthesis conditions were m (activation product)/m (xerogel) of 3.92, n(H2O)/n (SiO2) of 25.8, and crystallization time of 12 h. The synthesized zeolite W was used to extract K+ ion from the simulated seawater. The synthesized zeolite W with the fluffier spindle morphology exhibited a higher K+ extraction capacity. The maximum exchange capacity of zeolite W for K+ ion reached 49.57 mg·g−1. The zeolite W synthesized by the gel‐like‐solid phase method possessed a superior K+ extraction capacity than that synthesized by the hydrothermal method when K‐feldspar was used as the raw material and an approximate K+ extraction capacity with that synthesized from chemical reagents. In addition, the recycling process of the mother liquor was designed. This work provides an effective way for the zeolite W synthesis and the resource utilization of K‐feldspar with advantages of high raw material utilization, low water content in the synthesis system, short crystallization time, and recyclable mother liquor after synthesis of zeolite W.

Biobased Symmetrical Fatty Amides for High Heat Deflection Temperature of Poly(l-lactide)-Based Materials

In this paper, we report the synthesis and the use of fatty bis-amides as nucleating agents for poly(l-lactide) (PLLA) to enhance its crystallization kinetics and its heat deflection temperature using short processing times. Bis-amides were synthesized in bulk from C18 fatty acid derivatives such as stearic acid, 12-hydroxystearic acid, oleic acid, or ricinoleic acid and a series of linear aliphatic diamines (C4, C6, C10, and C12) using a thermal process. The bis-amides were then mixed with neat PLLA through an extrusion process at different loadings (0.1, 0.5, 0.8, and 1 wt %) and the resulting materials were obtained by injection-molding. High degrees of crystallinity (>50%) could be achieved through short isothermal crystallization times such as 25 s at 110 °C and led to improved measured heat deflection temperatures nearing 120 °C in the best-case scenario. Such performance was achieved using the bis-amide obtained from the C4 diamine and stearic acid, which displayed the highest melting point of all the considered nucleating agents.

Solvent-free and low template content synthesis of Ti-Beta zeolite via interzeolite transformation for oxidative desulfurization

Solvent-free and low-template synthesis of zeolite materials is the future direction of zeolite production, which meets the requirements of green chemistry. Ti-Beta zeolite with opened channel systems of the 3-dimensional 12-membered ring is a promising industrial catalyst in the field of selective oxidations. Herein, nanosized Ti-Beta zeolites were successfully synthesized via interzeolite transformation of siliceous MOR zeolite using sample and commercially available tetraethylammonium hydroxide (TEAOH) as organic structure-directing agents under solvent-free and low-template-content (TEAOH/SiO2 = 0.2) conditions within a short crystallization time. The crystallization mechanism and Ti coordinated state were thoroughly investigated by numerous characterization techniques. It was found that the hydrothermal synthesis of Ti-Beta-M zeolites obeyed a liquid crystallization mechanism, during which pre-dissolution of the silicon source MOR zeolite was a critical step in achieving successful crystallization. Ti4+ ions mainly existed in the form of tetrahedrally coordinated states in zeolite framework. Thus Ti-Beta zeolites showed remarkable activity and reusability during the oxidative desulfurization of fuel oil. Moreover, the deactivated mechanism and regenerated method were also studied in detail. This work provides new guidance for solvent-free and low template content synthesis of metallosilicate zeolites.

Modulation of the spatial distribution of crystallizable emulsifiers in Pickering double emulsions

The unique role of the spatial distribution of crystallizable emulsifiers in regulating the structure and properties of double emulsions has been gradually recognized. Herein, we utilized crystallizable monoglycerides of different carbon chain length (GMS/GMP/GML) to “structuring” the intermediate oil phase of double emulsions during a two-stage emulsification process followed by a cooling treatment. A ternary eigenvector (I, M, E) based on the numerical processing of polarization images was invented to quantitatively characterize the distribution pattern of monoglycerides. Crystallization kinetics analysis and dissipative particle dynamic simulation were then employed to reveal the regulatory mechanism for the site-specific interface distribution behavior. Results suggested that the distribution pattern of monoglycerides could be pricesly tuned as the internal interface-, external interface- or oil-phase dominated one in double emulsions. The surface activity as well as crystallization rates of monoglycerides dominated the interfacial distribution kinetics, and the cooling gradient along the interface region further regulated their interfacial distribution potential. Specificly, shorter crystallization time (t1/2) made GMP molecules rapidly solidified in oil phase, leading to the oil phase domninate crystallization (0, M, 0), whereas, slow crystallization rate rendered GML and GMS with sufficient time to diffuse to the interface, thus forming interfacial crystals ((I, 0, 0) and (0, 0, E)). The sensitivity of GML to cooling gradient along the interface region led to its preferential external interface distribution under cooling treatment. The presented study explored novel strategies that can be used in characterizing and manipulating the distribution pattern of crystallizable emulsifiers in multi-interface emulsion systems.

Facile and selective approach towards synthesis of a series ZSM-5/ZSM-12 catalysts for methanol to hydrocarbons reactions: Applying different synthesis driving force and conditions

The use of ultrasonic waves was developed for synthesis of zeolites at shorter crystallization time with improving their desirable properties. A series of nanostructured ZSM-5/ZSM-12 composite zeolites with different Si/Al ratios and alkalinity using organic templates were prepared by hydrothermal and sonochemical synthesis methods. The physicochemical properties of synthesized nanocatalysts such as structure, morphology, textural, and acidity were characterized via XRD, FESEM, N2 physisorption, FTIR, TPD-NH3, TGA-DTG techniques. The results revealed that increasing the Si/Al ratio and alkalinity in the hydrothermal samples enhanced the crystallization, formation of amorphous microcrystals, and dominant phase of MFI with decreasing MTW competitive phase. Zeolites synthesized by high-temperature and short-time sonochemical method had higher crystallinity, less dominant phase of ZSM-5, smaller crystals, greater surface areas, higher concentration of Brønsted acid sites, and stronger strength of moderate/strong acid sites. The catalytic performance of the zeolites for MTH conversion was evaluated under a reaction temperature of 450 °C at different times on stream. The results showed that the sonochemical zeolite had a higher methanol conversion (100%), higher selectivity toward olefins (28% vs. 19%) with more C3=/C2= ratio (0.79 vs. 0.58), and lower alkanes selectivity (66% vs. 72%) after 240 min TOS.

Graphene oxide-assisted fast synthesis of hierarchical ZSM-11 with superior performance for benzene alkylation

Fast synthesis of zeolite with hydrothermal method is a challengeable topic. In this work, we reduced the crystallization time to ~1/3 of conventional method by adding a small amount of graphene oxide (GO) into ZSM-11 synthesis gel. The embedment of GO into ZSM-11 crystal was confirmed by XPS, TG, and Raman spectra, while it modified morphology, porosities, component, and surface acidity of ZSM-11 as characterized by SEM, TEM, XRF, N2-physisorbtion, NH3-TPD, and Py-IR. The non-classical nucleation, which governed the required crystallization time, was further proposed and evidenced by both experimental observations and molecular dynamic modeling. It clearly illustrated the positive role of GO on promoting the formation of meta-stable phase during non-classic nucleation, resulting into much shorter crystallization time. GO embedded ZSM-11 demonstrated high activity (reaction rate and TOF), improved selectivity, and superior stability for benzene alkylation with ethanol, which can be attributed to the regulated surface acidity and diffusion properties. This work opens up a new perspective to synthesize ZSM-11 zeolite with superior catalytic performance in a highly efficient and environmental manner.

Synthesis of low-silica SAPO-34 at lower hydrothermal temperature by additional pressure and its enhanced catalytic performance for methanol to olefin

A low hydrothermal temperature, short crystallization time and green strategy is developed for the synthesis of low-silica SAPO-34. The samples were prepared by adjusting the additional pressure with N 2 using TEA as the sole template. The pure SAPO-34 (SP-C4) was obtained only under pressure of 2.7 MPa which possessed the smaller crystal size and moderate acidity and showed enhanced the lifetime and light olefins selectivity in methanol to olefins. And the possible formation mechanism of low-silica SAPO-34 was proposed. • A green strategy is developed for the synthesis of SAPO-34 by additional pressure. • Synthesis of low-silica SAPO-34 at low hydrothermal temperature for short time. • The obtained SAPO-34 possesses the smaller crystal size and moderate acidity. • Enhanced the lifetime (520 min) and light olefins selectivity (85.0%).

Microwave synthesis conditions dependent catalytic performance of hydrothermally aged CuII-SSZ-13 for NH3-SCR of NO

To simplify the complicated synthetic techniques so that getting CuII-SSZ-13 zeolites with ideal structures and CuII cations distribution, and to interrogate CuII cations dynamics dependent NH3 mediated performance of selective catalytic reduction (NH3-SCR) of NO and hydrothermal stability, a microwave-assisted hydrothermal synthesis route was performed to prepare CuII exchanged SSZ-13 zeolite catalysts. The effects of synthetic temperature and time on the structure of SSZ-13 zeolite and NH3-SCR performance are clarified. The types and numbers of CuII species of fresh and hydrothermal aged samples were precisely explored. The NH3-SCR activity, N2 selectivity of fresh and aged CuII-SSZ-13 zeolites synthesized by different conditions are evaluated, respectively. Experimental characterizations demonstrate that the CuII-SSZ-13 zeolites can be synthesized with short crystallization time assisted with microwave treatment. The microwave synthesis temperature and time can affect the nucleation and growth process of SSZ-13 and thus resulting in SSZ-13 with different framework structures and various affinity to CuII ions. When the temperature and time are 175 °C and 9 h, the as-synthesized CuII-SSZ-13 sample shows a stable framework structure, large specific surface area, and more [Z2CuII] speciation. This sample also shows excellent catalytic activity and hydrothermal stability. Characterization results also show that the microwave treatment can strengthen the Al-O-Si bonds in the zeolite framework. Our work provides a facile strategy to synthesize CuII-SSZ-13 zeolite and atomic-level understanding of catalytic property and hydrothermal stability.

Structural/Texture Evolution During Facile Substitution of Ni into ZSM-5 Nanostructure vs. its Impregnation Dispersion Used in Selective Transformation of Methanol to Ethylene and Propylene.

The effect of two different modification methods for introducing Ni into the ZSM-5 framework was investigated under high-temperature synthesis conditions. The nickel was successfully introduced into the MFI structures at different crystallization conditions to enhance the physicochemical properties and catalytic performance. A series of impregnated Ni/ZSM-5 and isomorphous substituted NiZSM- 5 nanostructure catalysts were prepared hydrothermally at different high temperatures and within short times. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray (EDX), Brunner, Emmett and Teller-Barrett, Joyner and Halenda (BETBJH), Fourier transform infrared (FTIR) and Temperature-programmed desorption of ammonia (TPD-NH3) were applied to investigate the physicochemical properties. Although all the catalysts showed pure silica MFI-type nanosheets and coffin-like morphology, using the isomorphous substitution for Ni incorporation into the ZSM-5 framework led to the formation of materials with lower crystallinity, higher pore volume and stronger acidity compared to using impregnation method. Moreover, it was found that raising the hydrothermal temperature increased the crystallinity and enhanced the more uniform incorporation of Ni atoms in the crystalline structure of catalysts. TPD-NH3 analysis demonstrated that high crystallization temperature and short crystallization time of NiZSM-5(350-0.5) resulted in fewer weak acid sites and medium acid strength. The MTO catalytic performance was tested in a fixed bed reactor at 460ºC and GHSV=10500 cm3/gcat.h. A slightly different reaction pathway was proposed for the production of light olefins over impregnated Ni/ZSM-5 catalysts based on the role of NiO species. The enhanced methanol conversion for isomorphous substituted NiZSM-5 catalysts could be related to the most accessible active sites located inside the pores. The impregnated Ni/ZSM-5 catalyst prepared at low hydrothermal temperature showed the best catalytic performance, while the isomorphous substituted NiZSM-5 prepared at high temperature was found to be the active molecular sieve regarding the stability performance.

Formation of EMT/FAU intergrowth and nanosized SOD zeolites from synthesis gel of zeolite NaX containing ethanol

Ethanol can serve as an organic additive in zeolite synthesis due to the ease of availability and simple removal. It can influence the crystallization leading to zeolites with different phases and morphology. This study explores the effect of partial displacement of water in the synthesis gel of zeolite NaX by various amounts of ethanol. With one-pot synthesis, the gels with different ethanol/water molar ratios are crystallized 90 °C for 18 h under a static condition. The products are characterized by several techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning and transmission electron microscopy (SEM and TEM), nitrogen sorption analysis, inductively coupled plasma-optical emission spectrometry (ICP-OES), and thermogravimetric analysis (TGA). The ethanol/water molar ratio of 0.045 produces EMT/FAU intergrowth with a hollow structure and undefined shapes. The ratios of 0.412 and 0.628 give the aggregates of nanocrystalline SOD zeolite. Moreover, the molar ratios of 0.101, 0.174 and 0.273 provide a mixture of the three phases. All zeolite products contain both intrinsic micropores and interparticle mesopores. The higher ethanol/water molar ratio in the gel produces the zeolites with the lower Si/Al ratio due to the higher Al incorporation in the zeolite structure. In summary, we demonstrate alternative template-free approaches to synthesize EMT/FAU intergrowth and nanosized SOD zeolite with short crystallization time and low crystallization temperature. The finding is an example of ethanol influence on the crystallization to control the phase and morphology of zeolite.

Oxidative desulfurization of model oil over Ta-Beta zeolite synthesized via structural reconstruction

As to metallosilicate zeolites, ions with larger size such as Ta5+ in the gels greatly retarded their crystallization during the hydrothermal synthesis, affording long-winded synthesis periods, up-limited framework-substituted metal contents, or even frustrated outcome. An efficient hydrothermal synthesis strategy for metallosilicate, in this case of Ta framework-substituted *BEA zeolite, via structural reconstruction was proposed to stride the gap. The Ta content in our developed Ta-Beta-Re-50 zeolite achieved up to 5.48 % (Si/Ta = 52), breaking through the limitation of Ta contents for conventional method (Si/Ta > 100). Additionally, this Ta-Beta-Re zeolite possessed nanosized crystals (20–40 nm) and short crystallization time (8 h), significantly improving space-time yields of practical zeolite production. Through spectroscopic study, it was confirmed that the existence of zeolite structural units intensively facilitated the formation of nucleation and crystal growth. This innovative Ta-Beta zeolite demonstrated high catalytic performances for oxidation desulfurization, far outperforming traditional fluoride-mediated Ta-Beta-F, which was ascribed to its excellent diffusion properties and incredible high isolated Ta contents. Additionally, the catalytic performance of Ta-Beta-Re could be regenerated after simple calcination and the deactivation may be caused by pore blocking of organics. This work provides a new method for rationally design and construction of metallosilicate materials with high activity for catalytic oxidation applications, which can bridge the conceptual and technical gap between periodic trends and zeolite material synthesis.