Search

Background. Pyroptosis is a type of cell death that plays an important role in predicting prognosis and immunoregulation in cancers. However, the pyroptosis-related gene signature for prognosis and immune infiltration prediction has not been studied in breast cancer (BC). Methods. The Gene Expression Omnibus (GEO) and Cancer Genome Atlas (TCGA) databases were used to obtain the expression and clinical data of genes. 52 pyroptosis-related genes were obtained from TCGA-BC and estimated differentially expressed genes by the limma program. To categorize the molecular subtypes of pyroptosis-related genes, the ConsensusClusterPlus tool was utilized. Cox and Lasso regression analyses were used to create a signature. TCGA-BC dataset as the training set and the GSE37751 test set for risk research. Gene set enrichment analysis (GSEA) was used to conduct KEGG and GO studies of subtype groups. We also used the ssGSEA approach in the GSVA package to calculate the risk score of immune cells. Finally, pyroptosis-related genes in BC were validated using qPCR and immunohistochemical assays. Clone formation and EDU assays were used to explore the ability of signature genes to regulate the proliferation of BC cells. Results. Based on pyroptosis-related genes, the C1 and C2 subtypes were obtained. Survival analysis results showed that the C2 group had a better prognosis. Then, a three-gene signature (APOBEC3D, TNFRSF14, and RAC2) were created by Lasso regression analysis, which had a good prediction effect in the TCGA-BC and GSE37751 datasets. Our nomogram has a fair degree of accuracy in predicting the survival rates of BC patients. The pyroptosis-related signature has a good predictive effect in evaluating the tumour microenvironment score, 28 types of immune cells and response to immune checkpoint therapy. Finally, qPCR and immunohistochemistry staining results indicated that APOBEC3D, TNFRSF14, and RAC2 expression in BC tissues was low. The results of clone formation and EdU assays showed that high expression of signature genes inhibited the proliferation ability of BC cells. Conclusions. Based on pyroptosis-related genes (APOBEC3D, TNFRSF14, and RAC2), we built a novel prognostic molecular model for BC that might be used to assess prognostic risk and immune infiltration in BC patients. These signature genes are also tumor suppressor genes and may serve as potential targets for BC.

Highly selective synthesis of liquefied petroleum gas (LPG, C03, C04) from CO2 hydrogenation have realized over the In2O3/SSZ-13 bifunctional catalyst. The physicochemical properties of the bifunctional catalyst were characterized by X-ray diffraction spectroscopy (XRD), N2 physical adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and NH3 temperature-programmed desorption (NH3-TPD). The particle size effect of In2O3 and reaction conditions were investigated for CO2 hydrogenation to LPG over the In2O3/SSZ-13 bifunctional catalyst. Results indicate that CO2 conversion and CO selectivity are related to the particle size of In2O3, and fresh 5 nm In2O3 shows the highest CO2 conversion (11.7%) and the highest CO selectivity (61.0%), since it is more prone to reverse water gas reaction (RWGS). However, the hydrocarbon distribution does not exhibit a dependence of In2O3 size changes, and the selectivity of LPG maintains at 90% and the selectivity of propane reaches up to 76.8% due to the 8-MR micropores and strong acid sites of SSZ-13 zeolite. Additionally, the yield of LPG shows a volcano type with increasing reaction temperature, and the optimal reaction temperature is 370°C. Low space velocity is more favorable to the CO2 conversion, and LPG selectivity in hydrocarbon products still maintains about 90%. High reaction pressure is beneficial to improving the yield of LPG via promoting the secondary hydrogenation reaction over the SSZ-13 zeolite and inhibiting CO formation. Furthermore, no obvious deactivation is observed after a time on stream (TOS) of 100 h over the In2O3/SSZ-13 bifunctional catalyst at 350°C, 3 MPa and 9000 mL/(gcat·h). The research provides a new strategy for highly selective synthesis of LPG from CO2 hydrogenation.

Bifunctional catalysts using hierarchical ZSM-5 zeolite as a support have received more attention for their specific characteristic, which is in favor of producing middle distillate hydrocarbons in Fischer–Tropsch synthesis. The hierarchical structure together with the Bronsted acidity of ZSM-5 zeolites result in the secondary reaction for hydrocracking or isomerization of heavy hydrocarbons. Herein, hierarchical ZSM-5 zeolites with different acidities and mesopore volumes are synthesized by treating zeolites with TPAOH solution. The hierarchical zeolite supported CoMn catalysts are prepared by impregnation method, and all the catalysts are characterized by XRD, BET, XPS, CO/NH₃-TPD, and Py-IR. The results show that the 0.5 M TPAOH solution treated ZSM-5 (Z5-0.5M) possesses the largest mesopore volume and a proper Bronsted acidity. In addition, the Z5-0.5M supported CoMn catalyst exhibits a selectivity of jet fuel range (C₈–C₁₆) as high as 50%, which is much higher than the maximum of 41% predicted by the Anderson–Schulz–Flory model. Moreover, the effect of cobalt loading indicates that the increased cobalt loading leads to the enhancement of CO conversion and the upshift to heavier hydrocarbons.

The present work reports on the promoting effects of rare earth elements (La, Ce and Y) to FeK/Al2O3 catalysts on liquid hydrocarbons from CO2 hydrogenation. The addition of La, Ce and Y can both improve the selectivity of C5+ hydrocarbons and reduce the selectivity of CH4. The C5+ selectivity can enhance to about 60 % with CH4 selectivity of around 11 % at CO2 conversions above 20 %. N2 adsorption–desorption, in situ XRD, H2–TPR, CO2/H2–TPD, HRTEM and XPS are used to characterize the FeK/Al2O3 and FeK/M-Al2O3 (M = La, Ce, Y) catalysts. The results show that the introduction of rare earth elements into the FeK/Al2O3 catalyst obviously reduces the adsorption of H2, which suppresses the CH4 formation. On the other hand, rare earth elements also promote the adsorbed CO2 species, which leads to the enhanced liquid hydrocarbons selectivity. Finally, the tailored CO2/H2 ratio of CO2 and H2 adsorption on the catalyst surface can influence the catalyst activity and the product selectivity evidently.

Gamma-ray (gamma-ray) irradiation was introduced into zeolite synthesis. The crystallization process of zeolite NaA, NaY, Silicalite-1, and ZSM-5 were greatly accelerated. The crystallization time of NaA zeolite was significantly decreased to 18 h under gamma-ray irradiation at 20 degrees C, while more than 102 h was needed for the conventional process. Unexpectedly, more mesopores were created during this process, and thus the adsorption capacity of CO2 increased by 6-fold compared to the NaA prepared without gamma-ray irradiation. Solid experimental evidence and density function theory (DFT) calculations demonstrated that hydroxyl free radicals (OH*) generated by gamma-rays accelerated the crystallization of zeolite NaA. Besides NaA, mesoporous ZSM-5 with MFI topology was also successfully synthesized under gamma-ray irradiation, which possessed excellent catalytic performance for methanol conversion, suggesting the universality of this new synthetic strategy for various zeolites.

The Fischer–Tropsch synthesis (FTS) has been studied for decades; however, it is very difficult to simultaneously obtain a high one-pass CO conversion and a high selectivity of long-chain (C5+) hyd...

Summary The direct transformation of syngas into C2-oxygenates (e.g., ethanol) is in great demand, but it is still challenging because of the low selectivity and poor catalyst stability. Here, we overcome the issues and report a zeolite-fixation methodology to strengthen the transformation. By employing the extensively investigated RhMn catalyst, the silicate-1 zeolite-fixed RhMn nanoparticles with core-shell structure (RhMn@S-1) exhibit high efficacy for the C2 oxygenates production from syngas, giving oxygenate selectivity at 40.3% under CO conversion of 42.4% (C2-oxygenate selectivity at 88.3% in the total oxygenates), which decidedly outperforms the previous catalysts in direct syngas-to-ethanol transformation. Multiple studies demonstrate that the rigid zeolite framework efficiently stabilizes the Mn-O-Rhδ+ structure, known as the crucial site for C2-oxygenate formation. In the long-term test, the RhMn@S-1 catalyst exhibits constant C2-oxygenate productivities with superior durability. This investigation demonstrates the powerful siliceous zeolite support in the C2-oxygenate production, which has not been explored previously.

A series of mesoporous ZSM-5 zeolite supported cobalt-based catalysts with the cobalt crystal sizes in the range of 4.5-18.1 nm were prepared for syngas conversion. The highly selective synthesis of various liquid fuels including gasoline, jet fuel and diesel range hydrocarbons is achieved with different cobalt nanoparticle sizes.

Isomorphous substitution is an important approach in modifying the acidity and pore structure of nanoscale SAPO-34 zeolites, which can bring about active sites stemming from heteroatoms. However, i...

The increasing demands for catalysts with improved accessibility to reactants call for a rational synthesis of nanosized zeolites. Herein we developed a facile approach for highly crystalline MFI-type (Silicalite-1 and ZSM-5) and beta zeolites with variable Si/Al ratios and high yield. This was achieved by kinetically decoupling the nucleation from the growth process of the zeolites in a highly concentrated gel system via a temperature-staged treatment. The carefully controlled low-water environment ensures only nucleation in stage I (aging), and hence the generation of abundant nuclei for the subsequent rapid crystallization within a self-confined space at stage II (growth). The method, without using expensive templates or additives, allows the syntheses of nanosized, well-isolated ZSM-5 (Si/Al = 100–∞, 36–88 nm, yield >85%) and Beta (Si/Al = 25–100, 21–66 nm, yield >95%). The ultra-small crystal size endows ZSM-5 zeolites with good catalytic activity, product selectivity and remarkably longer lifetime in methanol conversion reactions.

The zeolite materials have been industrially used in the thermal catalysis, but their function in photocatalysis has not been fully explored. Here we report that zeolites as supports could strength...

Because lower olefins (C-2(=)-C-4(=)) are important bulk petrochemicals, their direct production from CO2 hydrogenation is highly attractive. However, the selectivity towards C-2(=)-C-4(=) by the modified Fischer-Tropsch synthesis is restricted to 56.7 % with high undesired methane selectivity. Here, a series of bifunctional catalysts containing In2O3-ZnZrOx oxides and various SAPO-34 zeolites with different crystal sizes (0.4-1.5 mu m) and pore structures was developed for the production of lower olefins by CO2 hydrogenation. The C-2(=)-C-4(=) selectivity reached as high as 85 % among all hydrocarbons with very low CH4 selectivity of only 1 % at a CO2 conversion of 17 %. This demonstrated that the small crystal size, hierarchical pore structure, and appropriate amount of Bronsted acid sites of SAPO-34 endowed the bifunctional catalysts with high C-2(=)-C-4(=) selectivity. This work shows an efficient way for developing bifunctional catalysts for direct CO2 hydrogenation to lower olefins.

Conversion of carbon dioxide (CO2) to fuels and chemicals with the help of renewable hydrogen (H2) is a very attractive approach to reduce CO2 emissions and replace dwindling fossil fuels. However,...

BackgroundCirculating tumor cells (CTCs) can be detected in peripheral blood of many malignant tumor cases, but low numbers of CTCs can be detected in peripheral blood of healthy individuals as well as patients with benign tumors. It is not known whether peripheral CTC counts differ between patients with benign gastric diseases and those with gastric cancer. It is still unknown whether peripheral CTC counts can act as a superior factor to assess the clinicopathological stage in gastric cancer.MethodsComparative analysis of preoperative peripheral CTC counts was completed in patients with gastric polyps and non-metastatic gastric cancer. Correlation analysis was carried out between peripheral CTC counts and histological differentiation types, histopathological types, depth of tumor infiltration, positive lymph node metastasis rate and tumor markers (CEA, CA19-9 and CA72-4).ResultsPatients with gastric cancer had higher CTC counts than those with gastric polyps (3.05 ± 0.48/3.2 ml vs 0.69 ± 0.17/3.2 ml, P 1/3.2 ml) diagnosed with either gastric polyps or gastric cancer (X2 = 9.67, P X2 = 2.43, P P>0.05). Significant CTC counts difference was observed between mucous membrane invasive group and muscular layer invasive group in gastric cancer (3.00 ± 0.33/3.2 ml vs 1.4 ± 0.4/3.2 ml, P P>0.05). CTC counts could show higher positive ratio when compared with CEA, CA19-9 and CA72-4 respectively (X2 = 34.37, X2 = 36.89, X2 = 29.72, P X2 = 16.71, P

Venous thromboembolism (VTE) is a serious complication encountered in surgical practice. The purpose of this study was to identify changes in coagulation status and deep vein flow parameters, within 24 h postoperatively, for patients undergoing laparoscopic total extraperitoneal inguinal hernia repair (TEP). For 144 patients undergoing TEP, coagulation markers including prothrombin time (PT), partial thromboplastin time, thrombin time, D-dimer, fibrinogen, fibrin degradation products (FDP), and international normalized ratio (INR) were monitored preoperatively and in the first morning postoperatively. Echo-Doppler recordings preoperatively and again within 24 h postoperatively were completed for 23 patients to monitor lower extremity deep vein flow parameters including speed of flow (cm/s), diameter (cm), and cross-sectional area (cm2). Clinically significant VTE and other complications were recorded. No significant VTE were diagnosed. Significant increases were seen in the first morning postoperatively for PT, D-dimer, FDP, and INR (P

Nano-scale SAPO-34 zeolites were successfully synthesized under atmospheric pressure for the first time through a dry gel conversion route with the assistance of magnesium aluminum silicate (Al2MgO8Si2). Under atmospheric pressure, the crystallization, calcination, and even catalytic evaluation of SAPO-34 can be carried out consecutively in the same fixed-bed reactor. Characterization and systematic studies indicated that the use of crystal seeds can improve the relative crystallinity of SAPO-34, and the as-synthesized SAPO-34 exhibits relatively high crystallinity, a high surface area and a uniform crystal size of 25 nm. Compared with conventional SAPO-34, the nano-scale SAPO-34 exhibited a higher selectivity to light olefins (83.6%) when methanol is completely converted. These results offer a potential way to synthesize zeolites by a safe and sustainable process under atmospheric pressure.

Direct production of lower olefins (C2=−C4=: ethylene, propylene and butylene), basic carbon-based building blocks, from carbon dioxide (CO2) hydrogenation is highly attractive, although the selectivity towards olefins has been too low. Here we present a series of bifunctional catalysts contained indium-zirconium composite oxides with different In:Zr atomic ratios and SAPO-34 zeolite, which can achieve a selectivity for C2=–C4= as high as 65–80% and that for C2–C4 of 96% with only about 2.5% methane among the hydrocarbon products at CO2 conversion of 15–27%. The selectivity of CO via the reverse water gas shift reaction is lower than 70%. The product distribution is completely different from that obtained via CO2-based Fischer-Tropsch synthesis and deviates greatly from the classical Anderson-Schulz-Flory distribution. The zirconium component plays a critical role in determining the physicochemical properties and catalytic performance of bifunctional catalysts. Catalyst characterization and density functional theory calculations demonstrate that the incorporation of a certain amount of zirconium can create more oxygen vacancy sites, stabilize the intermediates in CO2 hydrogenation and prevent the sintering of the active nanoparticles, thus leading to significantly enhanced catalytic activity, selectivity of hydrocarbons and stability for direct CO2 hydrogenation to lower olefins at the relatively high reaction temperature of 380 °C.

Direct oxidation of methane to formic acid under mild conditions is an attractive and challenging topic for methane upgrade. Fe-containing MFI-type zeolite (ZSM-5) has been recognized as a potential catalyst for this reaction. Herein, we demonstrate a simple method to crack the Fe/ZSM-5 into nanosized crystals and translate the isolated Fe3+ located in or outside the framework to extra-framework Fe ensemble species (dimer, oligomer and cluster) through high energy ball milling. The resultant catalysts exhibit up to 148% times increase in activity and provide higher formic acid selectivity and reliable stability for methane direct oxidation to formic acid with H2O2 as oxidant. The turnover frequency of C1 products over a 0.03%Fe/ZSM-5 catalyst is as high as 8380 h−1 with 96% of formic acid selectivity at 70 °C. Our work provides a valuable example for the design of an efficient catalyst for methane oxidation or even other light hydrocarbon carbohydrate oxidation processes.

SAPO-34 zeolite with a butterfly patterned hierarchical pore system and high relative crystallinity was synthesized by a melting-assisted solvent-free route. Oxalic acid in the solid state was used as the etching agent through a facile thermal treatment of the parent SAPO-34. The resultant zeolite exhibited complete methanol conversion, high C2=–C4= selectivity (>91%) and a long lifetime in the MTO process.

Acidity controlled Pt/ZSM-22 catalysts for n-dodecane hydroisomerization were explored through a simple and efficient post-treatment with different NaOH concentrations, and then the resulting samples were characterized using acid measurement, XRD, SEM, TEM, XRF and XPS. It appeared that the high crystallinity, uniform morphology and textural structure almost remained even after the alkaline-treatment of the parent zeolite with a low Si/Al ratio (∼20). However, the distribution of acid sites, and in particular the Bronsted acidity, changed which then affected the catalytic performance. This originates from the Bronsted acid sites of the parent catalyst being partially blocked. With the acid sites optimized using the alkali treatment, the selectivity for isomers increased from 59.5% (parent sample) to 87.3% (treated sample) with the yield increasing from 43.3% to 69.8%. Thus, such an ordinary alkaline treatment proved to be promising in the n-paraffin hydroisomerization for the cleaner production of lubricating oil based stocks.

Hydrogen is a promising candidate to replace the exhausting fossil fuels. However, it is still a big challenge for hydrogen storage. Liquid organic hydrogen carrier (LOHC), which possesses high safety and purity, easy transport and reversibility, is highly attractive for hydrogen storage. Herein we report a new reusable bimetallic Pd-Rh nanoparticles (NPs) catalyst with synergy effect, boosting both the hydrogenation of N-ethylcarbazole (NEC) and dehydrogenation of dodecahydro-N-ethylcarbazole (12H-NEC), which allows multiple cycles of reversible high-weight% hydrogen storage and uptake in short reaction time. Various ex- and in-situ characterizations evidenced that the superior activity was attributed to the bimetallic Pd-Rh NPs cluster structure on the surface of γ-Al2O3 support. The mechanism of NEC hydrogenation over the Pd-Rh catalyst was proposed and verified by density functional theory (DFT) calculations. Such a strategy can be extended to other LOHCs and sheds light onto the development of LOHCs as energy vectors.

Direct conversion of carbon dioxide (CO2) into lower olefins (C2=–C4=), generally referring to ethylene, propylene, and butylene, is highly attractive as a sustainable production route for its great significance in greenhouse gas control and fossil fuel substitution, but such a route always tends to be low in selectivity toward olefins. Here we present a bifunctional catalysis process that offers C2=–C4= selectivity as high as 80% and C2–C4 selectivity around 93% at more than 35% CO2 conversion. This is achieved by a bifunctional catalyst composed of indium–zirconium composite oxide and SAPO-34 zeolite, which is responsible for CO2 activation and selective C–C coupling, respectively. We demonstrate that both the precise control of oxygen vacancies on the oxide surface and the integration manner of the components are crucial in the direct production of lower olefins from CO2 hydrogenation. No obvious deactivation is observed over 150 h, indicating a promising potential for industrial application.

Although considerable progress has been made in carbon dioxide (CO2) hydrogenation to various C1 chemicals, it is still a great challenge to synthesize value-added products with two or more carbons, such as gasoline, directly from CO2 because of the extreme inertness of CO2 and a high C-C coupling barrier. Here we present a bifunctional catalyst composed of reducible indium oxides (In2O3) and zeolites that yields a high selectivity to gasoline-range hydrocarbons (78.6%) with a very low methane selectivity (1%). The oxygen vacancies on the In2O3 surfaces activate CO2 and hydrogen to form methanol, and C-C coupling subsequently occurs inside zeolite pores to produce gasoline-range hydrocarbons with a high octane number. The proximity of these two components plays a crucial role in suppressing the undesired reverse water gas shift reaction and giving a high selectivity for gasoline-range hydrocarbons. Moreover, the pellet catalyst exhibits a much better performance during an industry-relevant test, which suggests promising prospects for industrial applications.

H-type aluminosilicate zeolites are extensively used as solid-acid catalysts and support materials in industrial catalysis. However, the conventional synthesis methods involving hydrothermal syntheses and ion-exchange processes suffer from severe water pollution and toxic gas emissions. Herein, H-type MFI zeolite catalysts with a unique stacked structure were directly synthesized in the presence of NH4F and with the help of zeolite confinement through a solvent-free route without further ion-exchange procedures. A range of ex situ and in situ characterization procedures were used to provide evidence of the simultaneous use of pre-made ZSM-5 and NH4F as a confined Al source and mineralizer, respectively. The confined zeolite framework of ZSM-5 prevented the formation of AlFx species between NH4F and Al atoms, ensuring that the prepared samples had desirable acidic properties. Moreover, the resulting morphology could be controlled by using different silica substrates. The obtained H-type MFI zeolites showed excellent catalytic performance in methanol-to-gasoline reactions owing to their unique structure and directly exposed acidic sites. The developed one-pot strategy provides an alternative method for the facile synthesis of H-type zeolites with defined morphology.

Direct CO2 hydrogenation to high-value chemicals and fuels have received considerable attention. Nevertheless, efficiently producing aromatics with controllable aromatics distribution remains a great challenge. Herein, we report a series of bifunctional catalysts composed of highly active ZnZrOx oxides and nanocrystal HZSM-5 zeolites with the b-axis length ranging from 0.06 to 1.41 μm, which enable direct CO2 hydrogenation into aromatics with high selectivity of 55∼75 %. The CO2 conversion is up to 17.5 % with CO selectivity as low as 23.8 % mainly due to the affluent Bronsted acid sites and a large number of mesopores in HZSM-5 nanocrystal clusters with chain-like morphology. We demonstrate that a proper extension of the b-axis length of HZSM-5 can increase the selectivity of para-xylene (PX) while shortening the length of b-axis favors the formation of tetramethylbenzene (TeMB). The maximum selectivities of PX and TeMB in aromatics can reach to 28.9 % and 74.1 %, respectively.

ZSM-5 crystals with controllable c-axis length were successfully synthesized through a one-pot solvent-free route, with urea as an additive. X-ray diffraction patterns (XRD) show that the prepared samples exhibit high crystallinity. N2 adsorption–desorption isotherms and mercury intrusion porosimetry (MIP) analysis together with TEM observations indicate that micro-, meso-, and macropores exist in the obtained samples. Catalytic tests for the methanol to gasoline (MTG) conversion showed that the prepared c-axis oriented hierarchical ZSM-5, which allow fast mass transfer, exhibited both 100 % methanol conversion and far longer lifetime (900 h) than those of ZSM-5 with conventional morphology (350 h) in the MTG reaction. The enhanced MTG performance by the c-axis oriented zeolite under one-pot solvent-free synthesis is of great importance as it is easily scaled-up for industrial applications.

Fast deactivation of catalyst is the main problem in methanol-to-aromatics (MTA) process. Herein, Zn-containing HZSM-5 zeolites with hierarchical pores (H-Zn/HZSM-5) were prepared by treating directly synthesized Zn/HZSM-5 with NaOH solution. The changes in crystallinity, acidity and textural properties of Zn/HZSM-5 before and after alkali treatment were characterized by X-ray diffraction, NH3-TPD, 27Al MAS-NMR, N2 physisorption, X-ray fluorescence and TEM techniques. MTA reaction under the operating conditions of T = 400 °C and WHSV = 2.5 h−1 showed that the aromatic yield was improved from 41.4% for HZSM-5 to 55.3%. Furthermore, H-Zn/HZSM-5 exhibited a high initial space time yield of 0.62 g gcat−1 h−1 and a long lifetime up to 120 h. These results could be ascribed to the hierarchical pores and the providential acidity, which enhanced the adsorption and diffusion of intermediates/products during the reaction.

The acidic property of a BEA zeolite prepared by a seed-directed synthesis (SDS) method without organic structure directing agent (OSDA) was analyzed by a method of ammonia infrared / mass spectroscopic (IRMS) temperature-programmed desorption (TPD). The number of Brønsted acid sites on the SDS-BEA zeolite was larger than that on a conventional BEA zeolite synthesized from using OSDA. The enthalpy of ammonia desorption, distributed mainly in a range between 115 and 145 kJ mol-1, was in agreement with the acid strength region generated by isomorphous substitution of Si4+ by Al3+ in the BEA framework. These observations confirm that the microstructure around the incorporated Al in the SDS-BEA zeolite was equivalent to that in the conventional one.

m -xylene isomerization over zeolites is of great importance because of the shortage of p -xylene currently. Here, we show an organotemplate-free, seed-directed, and rapid synthesis of Al-rich zeolite MTT (denoted as ZJM-6) with improved catalytic performance in isomerization of m -xylene to p -xylene. Physicochemical characterizations including XRD, SEM, Ar sorption isotherms, 27 Al NMR, and NH 3 -TPD show that the zeolitic product has good crystallinity, uniform crystals, high surface area, tetrahedral Al 3+ species, and abundant acidic sites. Interestingly, the crystallization of ZJM-6 takes very short time (5 h at 170 °C), compared with conventional MTT zeolites (20 h at 170 °C). Very importantly, catalytic tests for m -xylene isomerization show that H-form of ZJM-6 zeolite exhibits superior performance, which could be potentially important for industrial applications of ZJM-6 zeolite as a candidate in the future.

SAPO-34 molecular sieves with different crystal morphologies were synthesized under microwave conditions. The type of organic templates, crystallization time and temperature were optimized to control the synthesis. These SAPO-34 samples were characterized by XRD, SEM, EDX, TG, nitrogen adsorption–desorption, NH3-TPD and solid state MAS NMR techniques. It was found that the crystallization conditions greatly affected the crystal morphology, textural data, Si incorporation and acidity of SAPO-34. Pure SAPO-34 with uniform sphere particles of 20 nm was obtained after crystallization at 165 °C for 0.75 h under microwave conditions using TEAOH as the template. Raising the temperature to 220 °C and prolonging the crystallization time to 2 h led to the formation of nano sheet-like SAPO-34 with a BET surface area of 593 m2/g. NH3-TPD profiles showed that low crystallization temperature and short crystallization time resulted in fewer weak acid sites and strong acid sites, while higher crystallization temperature and longer crystallization time increased the amount of both acid sites, which may benefit the methanol to olefins (MTO) reaction. The nano sheet-like SAPO-34 exhibited 100 % methanol conversion for 380 min during the MTO process, an ethylene selectivity of 51.77 % and a C 2 = –C 4 = selectivity of 90.20 %. The result was much better than that of the sample with a larger cubic morphology of 1.5–2.5 μm synthesized under hydrothermal conditions, on which the 100 % methanol conversion could only be kept for 212 min as well as an ethylene selectivity of 49.84 % and a C 2 = –C 4 = selectivity of 86.81 %. The unique morphology of the nano sheet-like SAPO-34 decreased its coke formation rate, which might be responsible for its improved catalytic performance.

Small-pore zeolite levyne has been successfully synthesized following an organotemplate-free route using RUB-50 zeolite as seeds with the aid of a small amount of alcohols. Physicochemical characterization with a combination of techniques including XRD, N 2 adsorption, FE-SEM, 27 Al and 29 Si NMR, and TPD-NH 3 shows that the zeolitic product from this seed-directed organotemplate-free synthesis approach (designated as LEV-SDS) has good crystallinity, high surface area, uniform crystals, tetrahedral Al 3+ species, and abundant acidic sites. It is also found that alcohols play an important role in preparation of LEV-SDS zeolite by inhibiting the formation of MOR zeolite. Catalytic tests for the conversion of methanol-to-olefins (MTO) show that H-form of LEV-SDS zeolite exhibits good conversion of methanol and high selectivities for ethylene and propylene, which could be potentially important for using LEV-SDS zeolite as a catalyst in MTO reaction.

The modern synthesis of zeolites typically uses organic structure-directing agents. Therefore, the developing of new templates is part of zeolite research. The design and synthesis of Cu-SSZ-13 using a novel template of a low-cost copper amine complex (Cu2+ coordinated with tetraethylenepentamine) were reported, where the copper amine complex is both a template for synthesizing the SSZ-13 structure and a source of copper species in the zeolite. The calculated size of the complex (0.728 nm x 0.922 nm) matches well with the CHA cages (0.73 nm x 1.2 nm), which are the building units of the SSZ-13 zeolite. Various techniques were used to investigate the chemical and physical properties of the synthesized zeolite. The results showed that the sample has the SSZ-13 zeolite structure, high crystallinity, adjustable Si/Al ratios, and controllable copper loading. Catalytic tests using the selective catalytic reduction of NOx with NH3 showed that the Cu-SSZ-13 was a superior catalyst, and it can be important for the abatement of environmentally harmful NOx.

The organotemplate-free route for syntheses of aluminosilicate ZSM-34 zeolite and its heteroatom-substituted analogues (B, Ga, and Fe) in the presence of zeolite L seeds solution has been extensively investigated. Many factors such as the amount of zeolite L seeds solution, SiO2/Na2O ratio in the starting aluminosilicate gel, crystallization temperature, and time influence the crystallization of ZSM-34 zeolite significantly. The pure phase of ZSM-34 zeolite could only be obtained in a narrow phase diagram of Na2O−Al2O3−SiO2−H2O by a comprehensive consideration of these factors. Heteroatoms such as B, Ga, and Fe substituted ZSM-34 zeolites can also be synthesized by this organotemplate-free route. Catalytic tests in the conversion of methanol to olefins (MTO) at the temperature of 400 °C and weight hourly space velocity (WHSV) of 0.5 h−1 over aluminosilicate ZSM-34 and its analogues containing framework B and Ga show that these ZSM-34 catalysts exhibit higher selectivities for ethylene and propylene (>80%)...

The drumstick tree ( Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we report a high-quality draft genome sequence of M. oleifera . This assembly represents 91.78% of the estimated genome size and contains 19,465 protein-coding genes. Comparative genomic analysis between M. oleifera and related woody plant genomes helps clarify the general evolution of this species, while the identification of several species-specific gene families and positively selected genes in M. oleifera may help identify genes related to M. oleifera ’s high protein content, fast-growth, heat and stress tolerance. This reference genome greatly extends the basic research on M. oleifera , and may further promote applying genomics to enhanced breeding and improvement of M. oleifera .

We present an optical hygrometer based on cavity ring-down spectroscopy (CRDS). By using different absorption lines, we are able to determine the relative concentration of water vapor from a few percent down to the 10-12 level.

Mesoporous zeolites are useful solid catalysts for conversion of bulky molecules because they offer fast mass transfer along with size and shape selectivity. We report here the successful synthesis of mesoporous aluminosilicate zeolite Beta from a commercial cationic polymer that acts as a dual-function template to generate zeolitic micropores and mesopores simultaneously. This is the first demonstration of a single nonsurfactant polymer acting as such a template. Using high-resolution electron microscopy and tomography, we discovered that the resulting material (Beta-MS) has abundant and highly interconnected mesopores. More importantly, we demonstrated using a three-dimensional electron diffraction technique that each Beta-MS particle is a single crystal, whereas most previously reported mesoporous zeolites are comprised of nanosized zeolitic grains with random orientations. The use of nonsurfactant templates is essential to gaining single-crystalline mesoporous zeolites. The single-crystalline nature endows Beta-MS with better hydrothermal stability compared with surfactant-derived mesoporous zeolite Beta. Beta-MS also exhibited remarkably higher catalytic activity than did conventional zeolite Beta in acid-catalyzed reactions involving large molecules.

A novel synthetic route is designed, employing both high temperature and a nontoxic organic structure-directing agent (SDA), for the synthesis of high silica zeolite Y. The N-methylpyridinium used as an organic SDA is stable during the synthesis, and the high silica zeolite Y shows high hydrothermal stability and good catalytic performance, as well as excellent adsorptive properties.

As important industrial materials, microporous zeolites are necessarily synthesized in the presence of solvents such as in hydrothermal, solvothermal, and ionothermal routes. We demonstrate here a simple and generalized solvent-free route for synthesizing various types of zeolites by mixing, grinding, and heating solid raw materials. Compared with conventional hydrothermal route, the avoidance of solvents in the synthesis not only significantly reduces the waste production, but also greatly increases the yield of zeolite products. In addition, the use of starting solid raw materials remarkably enhances the synthesis efficiency and reduces the use of raw materials, energy, and costs.