Preparation and Characterization of Zeolite ZSM-5 in the Template: Effect of Crystallization Time on the Structure and Textural Properties

2012 ◽  
Vol 727-728 ◽  
pp. 1233-1237
Author(s):  
Aécio B. Sousa ◽  
Antusia dos S. Barbosa ◽  
Meiry Glaúcia Freire Rodrigues ◽  
Herve M. Laborde
Keyword(s):  
Low Cost ◽  
Textural Properties ◽  
Infrared Region ◽  
Bet Surface Area ◽  
Crystallization Time ◽  
Secondary Phases ◽  
Synthesis Time ◽  
Technological Impact ◽  
The Times

The preparation of ZSM-5 templates in the absence of organics is an area of high technological impact. These are responsible for the enhancement of the final products (zeolites). Therefore, the preparation of zeolites in the absence of template allows a compromise covering the low cost and environment. This study aimed to investigate the influence of synthesis time in the preparation of ZSM-5. This zeolite was prepared by hydrothermal synthesis, using as co-template (C2H5OH) and addition of seeds. The times of synthesis used were 3 to 5 days. The solids were characterized by XRD, BET and Spectroscopy in the infrared region. Through the results obtained with XRD, it was observed that all samples showed characteristic peaks of MFI structure of the group at intervals of 2θ = 7-9° and 23-25°, showing no presence of secondary phases. BET surface area showed a corresponding literature. The infrared showed bands characteristic of ZSM-5.

scholarly journals Characterization and comparison of walnut shells-based activated carbons and their adsorptive properties

2020 ◽  
Vol 38 (9-10) ◽  
pp. 450-463
Author(s):  
Xiya Li ◽  
Jieqiong Qiu ◽  
Yiqi Hu ◽  
Xiaoyuan Ren ◽  
Lu He ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Activated Carbons ◽  
Low Cost ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Hydrothermal Carbonization ◽  
Bet Surface Area ◽  
Activation Process ◽  
Walnut Shells ◽  
Adsorption Desorption

The production of low-cost biologically activated carbons (BACs) is urgent need of environmental protection and ecological sustainability. Hence, walnut shells were treated by traditional pyrolysis, direct KOH impregnation and combined activation composed of hydrothermal carbonization and two-step H3PO4- and pyrolysis-activation process to obtain porous carbon with high adsorption capacity. It was found that the best adsorption capacity for iodine and organic dye methylene blue (MB) can be obtained using the KOH impregnation at impregnation ratio of 1:1 or combined activation comprising of 2 h H3PO4 activation and 1 h pyrolysis activation at 1000°C. The produced KOH, H3PO4/pyrolysis activated BACs at the optimum conditions are superior to that of commercial ACs, 9.4 and 1.3 times for MB removal, 4 and 4.5 times for iodine number respectively. Characterization results demonstrated their porous structure with very good textural properties such as high BET surface area (1689.1 m2/g, 1545.3 m2/g) and high total pore volume (0.94 cm3/g, 0.96 cm3/g). The N2 adsorption-desorption isotherm of H3PO4/pyrolysis activated hydrochar suggested the co-existence of micro and meso-pores. Moreover, they are more effective for the removal of Fe(III) and Cr(VI) from aqueous solution than the commercial AC, suggesting a promising application in the field of water treatment.

Preparation and Characterization of MCM-22 Zeolite by Varying-Temperature Hydrothermal Synthesis

2011 ◽  
Vol 197-198 ◽  
pp. 1587-1590
Author(s):  
Yue Cheng ◽  
Xiao Yuan Su ◽  
Mang Lu
Keyword(s):  
Hydrothermal Method ◽  
Amorphous Material ◽  
Sem Analysis ◽  
Bet Surface Area ◽  
N2 Adsorption ◽  
Tem Analysis ◽  
Synthesis Time ◽  
Xrd Pattern ◽  
Adsorption Desorption

MCM-22 zeolite of high crystallinity was synthesized with varying-temperature hydrothermal method. Zeolite was characterized by means of XRD, SEM, TEM and TG-DTA. XRD pattern showed that the sample was MCM-22 zeolite. SEM analysis indicated that the MCM-22 sample is in the form of thin platelet-like crystals, and no amorphous material. TEM analysis exhibited regular shaped aggregate assembled by the independent growth of many small flaky crystals. N2-adsorption/desorption analysis showed that the pore size and BET surface area of MCM-22 were 3.5 nm and 387.8 m2/g, respectively. By means of the varying-temperature hydrothermal method, synthesis time can be effectively reduced, and energy consumption also decreases.

scholarly journals Influence of desilication conditions on the shynthesis of herarchical zeolite Y

2019 ◽  
Vol 15 (28) ◽  
pp. 85-96
Author(s):  
Aída Luz Villa Holguín ◽  
Carlos Fernando Imbachí Gamba
Keyword(s):  
Surface Area ◽  
Treatment Time ◽  
Zeolite Y ◽  
Textural Properties ◽  
Bet Surface Area ◽  
Usy Zeolite ◽  
Relative Crystallinity ◽  
Hierarchical Zeolites ◽  
Synthesis Time ◽  
Synthesized Materials

Hierarchical zeolites were synthesized by two methodologies, following desilication procedures of commercial zeolites. Starting from USY zeolite (Zeolyst CBV720,Si/Al=15), the effect of the amount of CTAB in the desilication media and the hydrothermal treatment time on the synthesized materials were analyzed.The results showed that the surfactant amount has a higher influence on relative crystallinity (%RC) and textural properties of the materials than synthesis time. All the samples showed a lower BET surface area compared with the starting zeolite, although mesopore surface area increased from 210.33 to 467.30 m2/g in the case of Z720-75sample. In the case of USY zeolite withSi/Al=2.6 (ZeolystCBV500),a previous dealumination with H4EDTA and anacid washingwith Na2H2EDTAsteps were included.It was found that the micropore and the mesopore surface areasincreased 13.96% and 11.23%, respectively, compared with the parent zeolite; furthermore, the %RC was 99% after treatmentprocedures.

scholarly journals APPLICATION OF ZSM-5 AND ZSM-12 ZEOLITES (IN SODIUM AND AMMONICAL FORMS) IN THE BARIUM ADSORPTION

2019 ◽  
Vol 16 (31) ◽  
pp. 74-83
Author(s):  
Daniele da Silva OLIVEIRA ◽  
Wallas Douglas de Macêdo SOUZA ◽  
Luiz Di SOUZA ◽  
Anne Gabriella Dias SANTOS ◽  
Vinícius Patrício da Silva CALDEIRA
Keyword(s):  
High Selectivity ◽  
Produced Water ◽  
Low Cost ◽  
Textural Properties ◽  
Aquatic Environments ◽  
Technical Application ◽  
Barium Concentration ◽  
Treatment Technologies ◽  
The Times ◽  
Adsorption Desorption

Heavy metals are often released into aquatic environments through various sources of industrial processes. However, conventional treatment technologies demand high cost and/or are inefficient for the recovery of these resources. In this context, the technical application of adsorption has been highlighted by its simplicity and practicality, especially when zeolites are used as adsorbents due to their excellent physicalchemical and textural properties, among them: their high availability, high selectivity and low cost. The present work characterized and evaluated the performance of Na-ZSM-5, Na-ZSM-12, NH4-ZSM-5 and NH4-ZSM-12 zeolites on barium adsorption as an alternative for the treatment of produced water. The Na-ZSM-5 and Na-ZSM-12 zeolites were synthesized by the hydrothermal method and subjected to ion exchange to obtain the ammoniacal form (NH4-ZSM-5 and NH4-ZSM-12). The characterization was done by: DRX, SEM, FRX and Adsorption / Desorption of Nitrogen, and barium concentration was measured by Atomic Absorption Spectroscopy (AAS). The adsorption studies were conducted under agitation at the times of 1, 6, 12 and 24 h. The results were promising for this application, because the Na-ZSM-5 zeolite presented the highest adsorption capacity, a fact related to its textural properties (volume and area of micropores).

scholarly journals Synthesis and Characterization of Colloidal CZTS Nanocrystals by a Hot-Injection Method

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
A. Méndez-López ◽  
A. Morales-Acevedo ◽  
Y. J. Acosta-Silva ◽  
M. Ortega-López
Keyword(s):  
Thin Films ◽  
Low Cost ◽  
Synthesis And Characterization ◽  
Wurtzite Phase ◽  
Synthesis Time ◽  
Injection Method ◽  
Hot Injection ◽  
Average Size ◽  
Czts Nanocrystals

The present study reports the synthesis of colloidal Cu2ZnSnS4(CZTS) nanocrystals (average size ~4–9 nm) by a simple and low cost hot-injection method. These nanocrystals form larger particles with sizes around 40 nm. Oleylamine (OLA) was used as both the solvent and the nanocrystal stabilizer. The effect of the synthesis time on the structural, compositional, morphological, and optical properties was studied. As revealed by XRD, Raman, and TEM measurements all the prepared samples are comprised of both kesterite and wurtzite CZTS nanocrystals. The wurtzite phase contribution reduces as the reaction time is increased. The “bandgap” of the obtained nanoparticles tends to 1.52 eV for the larger synthesis times (24 h) which is suitable for an absorber layer in thin films solar cells.

scholarly journals Microstructure and Thermoelectric Properties of (Bi0.48Sb1.52)Te3 Thick Films Prepared with Tape Casting Method

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Low Cost ◽  
Thick Films ◽  
Tape Casting ◽  
Casting Process ◽  
Casting Method ◽  
Glass Substrates ◽  
Conductive Films ◽  
Casting Technology

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.

scholarly journals Towards Iron-Titanium Oxide Nanostructures from Ecuadorian Black Mineral Sands

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 122
Author(s):  
Karina J. Lagos ◽  
Bojan A. Marinkovic ◽  
Alexis Debut ◽  
Karla Vizuete ◽  
Víctor H. Guerrero ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Titanium Oxide ◽  
Low Cost ◽  
Mineral Resources ◽  
Added Value ◽  
Secondary Phases ◽  
Hydrothermal Route ◽  
Oxide Nanostructures ◽  
Transmission Electron ◽  
Pre Treatment

Ecuadorian black mineral sands were used as starting material for the production of iron-titanium oxide nanostructures. For this purpose, two types of mineral processing were carried out, one incorporating a pre-treatment before conducting an alkaline hydrothermal synthesis (NaOH 10 M at 180 °C for 72 h), and the other prescinding this first step. Nanosheet-assembled flowers and nanoparticle agglomerates were obtained from the procedure including the pre-treatment. Conversely, nanobelts and plate-like particles were prepared by the single hydrothermal route. The nanoscale features of the product morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The ilmenite and hematite molar fractions, within the ilmenite-hematite solid solution, in the as-synthetized samples were estimated by Brown’s approach using the computed values of unit-cell volumes from Le Bail adjustments of X-ray powder diffraction (XRPD) patterns. The resulting materials were mainly composed of Fe-rich ilmenite-hematite solid solutions (hematite molar contents ≥0.6). Secondary phases, which possibly belong to lepidocrocite-like or corrugated titanate structures, were also identified. The current study demonstrated the feasibility of employing Ecuadorian mineral resources as low-cost precursors to synthesize high-added-value nanostructures with promising applications in several fields.

scholarly journals Synthesis and characterization of analcime (ANA) zeolite using a kaolinitic rock

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniela Novembre ◽  
Domingo Gimeno
Keyword(s):  
Ambient Pressure ◽  
Added Value ◽  
Emission Spectrometry ◽  
Quantitative Phase Analysis ◽  
Crystallization Time ◽  
Experimental Protocol ◽  
Economic Point ◽  
Cell Parameters ◽  
Synthesis Protocol

AbstractAnalcime is nowadays an important component in dental porcelain systems, in heterogeneous catalysis, in the nanoelectronic field, in selective adsorption and in stomatology (dental filling and prosthesis). Analcime synthesis from an impure, silica-rich kaolinite rock coming from Romana (Sassari, Italy) is here presented. A synthesis protocol is proposed that aims to make an improvement of synthesis conditions compared to the past. The hydrothermal treatment is in fact here achieved without aging times and without the use of sodium silicate or other additional silica source reported in the literature. Lower calcination temperature, synthesis temperature and crystallization time are verified in this work. The kaolin is subjected to calcination at the temperature of 650 °C and then mixed with NaOH. The experiment is performed at ambient pressure and 170 ± 0.1 °C. The degree of purity of analcime is calculated in 97.57% at 10 h. Analcime is characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, inductively coupled plasma optical emission spectrometry and thermal analysis. Density is also calculated. Cell parameters and the amount of amorphous phase in the synthesis powders is estimated with quantitative phase analysis using the combined Rietveld and reference intensity ratio methods. The experimental conditions make the synthesis protocol particularly attractive from an economic point of view. Also this work does not use a commercial kaolin but silica-rich impure kaolinitic rock from a disused quarry. This further reduces the costs of the experimental protocol. It also gives the protocol an added value, as the synthesis of a useful mineral is obtained through the valorization of an otherwise unused georesource. Both chemical and physical characterization of analcime is satisfactory making the experimental protocol very promising for an industrial transfer.

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