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.

Life Time Improvement of Hierarchically Structured SAPO-34 Nanocatalyst in MTO Reaction via Applying Clinoptilolite, Investigating of Composite Design via RSM

2020 ◽  
Vol 23 ◽  
Author(s):  
Reza Yazdanpanah ◽  
Eshagh Moradiyan ◽  
Rouein Halladj ◽  
Sima Askari
Keyword(s):  
Surface Area ◽  
Natural Zeolite ◽  
Coke Formation ◽  
Life Time ◽  
Weight Percent ◽  
Light Olefins ◽  
Bet Surface Area ◽  
Relative Crystallinity ◽  
Mto Reaction ◽  
The Common

Aim and Objective: The research focuses on recent progress in the production of light olefins. Hence, the common catalyst of the reaction (SAPO-34) deactivates quickly because of coke formation, we reorganized the mechanism combining SAPO-34 with a natural zeolite in order to delay the deactivation time. Materials and Methods: The synthesis of nanocomposite catalyst was conducted hydrothermally using experimental design. Firstly, Clinoptilolite was modified using nitric acid in order to achieve nano scaled material. Then, the initial gel of the SAPO-34 was prepared using DEA, aluminum isopropoxide, phosphoric acid and TEOS as the organic template, sources of Aluminum, Phosphor, and Silicate, respectively. Finally, the modified zeolite was combined with SAPO-34's gel. Results: 20 different catalysts due to D-Optimal design were synthesized and the nanocomposite with 50 weight percent of SAPO-34, 4 hours Crystallization and early Clinoptilolite precipitation showed the highest relative crystallinity, partly high BET surface area and hierarchical structure. Conclusion: Different analysis illustrated the existence of both components. The most important property alteration of nanocomposite was the increment of pore mean diameters and reduction in pore volumes in comparison with free SAPO-34. Due to low price of Clinoptilolite, the new catalyst develops the economy of the process. Using this composite, according to formation of multi-sized pores located hierarchically on the surface of the catalyst and increased surface area, significant amounts of Ethylene and Propylene, in comparison with free SAPO-34, were produced, as well as deactivation time that was improved.

scholarly journals Synthesis of a high-surface area V2O5/TiO2–SiO2 catalyst and its application in the visible light photocatalytic degradation of methylene blue

RSC Advances ◽  
2019 ◽  
Vol 9 (42) ◽  
pp. 24368-24376 ◽  
Author(s):  
Ajay Kumar Adepu ◽  
Srinath Goskula ◽  
Suman Chirra ◽  
Suresh Siliveri ◽  
Sripal Reddy Gujjula ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Bet Surface Area ◽  
Titanium Silicate ◽  
Ft Ir ◽  
Synthesized Materials ◽  
Visible Light Photocatalytic

In the present study, we synthesized several high-surface area V2O5/TiO2–SiO2 catalysts (vanado titanium silicate, VTS). The synthesized materials are characterized by PXRD, FE-SEM/EDAX, TEM, BET-surface area, FT-IR, UV-Vis, XPS, fluorescence and photocatalytic studies.

Synthesis of Carbon Nanofiber-Titania-Cordierite Monolith Composite and its Application as Catalyst Support on Citral Hydrogenation

2012 ◽  
Vol 535-537 ◽  
pp. 178-185 ◽  
Author(s):  
Jie Zhu ◽  
Ming Shi Li ◽  
Mo Hong Lu
Keyword(s):  
Surface Area ◽  
Carbon Nanofiber ◽  
Sol Gel ◽  
Catalyst Support ◽  
Textural Properties ◽  
Mesoporous Structure ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
Tetrabutyl Titanate ◽  
Citral Hydrogenation

We reported the synthesis of a promising carbon nanofiber-titania-cordierite monolith composite (C/TiO2/monolith) and its application in citral hydrogenation. The composite was synthesized through two steps: TiO2 coating on the surface of the monolith with sol-gel method and the following carbon deposit by methane decomposition. C/TiO2/monolith was subsequently employed to prepare its supported palladium catalyst, Pd/C/TiO2/monolith and its catalytic performance was evaluated in selective hydrogenation of citral. Results revealed that 2.0 wt% tetrabutyl titanate sol in composite synthesis was the best in improving textural properties of C/TiO2/monolith. The optimal composite possessed a BET surface area of 39.4 m2/g and micropore area accounted for only 3.8% of its total BET surface area. It contained about 30 wt% of carbon, which was mainly composed of carbon nanofiber. Pd/C/TiO2/monolith exhibited the high citronellal selectivity (81%) at 90% citral conversion, which was attributed to the decrease of internal diffusion limitation due to its mesoporous structure.

Novel Base Catalysts by Nitridation of Zeolite Y: Characterization and Catalytic Evaluation

2010 ◽  
Vol 148-149 ◽  
pp. 1096-1099
Author(s):  
Gong Ming Peng ◽  
De Lian Yi ◽  
Lin Wu ◽  
Zhao Hui Ou Yang ◽  
Jian Guo Wang
Keyword(s):  
Surface Area ◽  
Zeolite Y ◽  
High Surface ◽  
High Surface Area ◽  
Diethyl Malonate ◽  
Bet Surface Area ◽  
In Situ Drifts ◽  
Base Catalysts ◽  
Diffuse Reflectance Infrared

Novel base catalysts were obtained by subjecting Y zeolites to nitridation. These materials were characterized by elemental analysis, X-ray diffraction, BET surface area analysis, In situ diffuse reflectance infrared fourier transform Spectroscopy (in situ DRIFTS), Pyrrole adsorption. The results indicated nitrogen-incorporated NaY zeolite was well ordered and possess high surface area and pore volume. In situ DRIFTS experiments confirmed that N atoms had been introduced into the framework by nitridation to form -NH2- or -NH- species. It was found that Lewis basicity of these oxynitride materials increased by the pyrrole adsorption. Furthmore, the basic catalytic properties of nitrogen-incorporated zeolites were evaluated by Knoevenagal condensation of benzaldehyde with diethyl malonate and enhanced yield of product was achieved.

scholarly journals Kinetics of Highly Active TiO2 Microspheres Formation in a Presence of Ethylammonium Nitrate Ionic Liquid

2018 ◽  
Author(s):  
Anna Gołąbiewska ◽  
Micaela Checa-Suárez ◽  
Marta Paszkiewicz-Gawron ◽  
Wojciech Lisowski ◽  
Edyta Raczuk ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Phenol Degradation ◽  
Bet Surface Area ◽  
Synthesis Time ◽  
X Ray ◽  
Highly Active

Spherical microparticles of TiO2 were synthesized by the ionic liquid-assisted solvothermal method at different reaction time (3, 6, 12 and 24h). The properties of the prepared photocatalysts were investigated by means of UV-vis diffuse-reflectance spectroscopy (DRS), BET surface area measurements, scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The results indicated that the efficiency of phenol degradation was related with a time of the solvothermal synthesis as determined for TiO2_EAN(1:1)_24h sample. Microparticles of TiO2_EAN(1:1)_3h formed during the only 3h of synthesis time revealed really high photoactivity under visible irradiation – 75%. This value increased to 80% and 82% after 12h and 24h, respectively. The photoactivity increase was accompanied by the increase of the specific surface area thus pores size, as well as ability to absorb UV-vis irradiation. The high efficiency of phenol degradation of IL-TiO2 photocatalysts was ascribed to the interaction between the surface of TiO2 and ionic liquid components (carbon and nitrogen).

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.

A Novel Zeolite-Containing Composite Material Synthesized via In Situ Crystallization

2014 ◽  
Vol 926-930 ◽  
pp. 32-35
Author(s):  
Shu Qin Zheng ◽  
Shao Ren ◽  
Jian Ce Zhang ◽  
Wei Zhu
Keyword(s):  
Composite Material ◽  
Surface Area ◽  
Pore Volume ◽  
Reaction Medium ◽  
Pronounced Effect ◽  
Bet Surface Area ◽  
Y Zeolite ◽  
Relative Crystallinity

A novel Y zeolite-containing composite material was prepared via in situ crystallization with sepiolite and catalyst residue as starting materials, of which the BET surface area is up to 582 m2/g, the pore volume is 0.43 cm3/g, the relative crystallinity is as high as 55.7 %, the surface is smooth and regular, and Y zeolite particles are in the range of 0.4-1.0 mirons, the composite contains large number Y zeolite with more meso-macro porous structure.The alkalinity in reaction medium has a pronounced effect on the relative crystallinity of Y zeolite.

CuO/CeO2 and CuO/PrO2-CeO2 Catalysts for Preferential Oxidation of CO

2013 ◽  
Vol 773 ◽  
pp. 601-605 ◽  
Author(s):  
Zhi Jun Zhao ◽  
Ruo Yu Wang ◽  
Qian Long Zhao ◽  
En Peng Wang ◽  
Hai Quan Su ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Pore Volume ◽  
Crucial Role ◽  
Textural Properties ◽  
Bet Surface Area ◽  
Oxidation Of Co ◽  
Preferential Oxidation Of Co ◽  
Adsorption Desorption

The CuO/CeO2and CuO/PrO2-CeO2catalysts were prepared by the hydrothermal method, and characterized via XRD, SEM and N2adsorption-desorption techniques. The study shows that the BET surface area and pore volume of the CuO/PrO2-CeO2catalysts increase with the increase of praseodymium content. The CuO/CeO2catalyst presents higher catalytic activity in compare with the CuO/PrO2-CeO2catalysts although the addition of praseodymium promotes textural properties of the CuO/CeO2catalysts, and it proves that the interaction of CuO and CeO2has a crucial role in CO-PROX.

scholarly journals On the Gas Storage Properties of 3D Porous Carbons Derived from Hyper-Crosslinked Polymers

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 588 ◽  
Author(s):  
Giorgio Gatti ◽  
Mina Errahali ◽  
Lorenzo Tei ◽  
Maurizio Cossi ◽  
Leonardo Marchese
Keyword(s):  
Thermal Treatment ◽  
Surface Area ◽  
Pore Volume ◽  
Chemical Activation ◽  
Chemical Characterization ◽  
Total Pore Volume ◽  
Textural Properties ◽  
Gas Storage ◽  
Bet Surface Area ◽  
Porous Carbons

The preparation of porous carbons by post-synthesis treatment of hypercrosslinked polymers is described, with a careful physico-chemical characterization, to obtain new materials for gas storage and separation. Different procedures, based on chemical and thermal activations, are considered; they include thermal treatment at 380 °C, and chemical activation with KOH followed by thermal treatment at 750 or 800 °C; the resulting materials are carefully characterized in their structural and textural properties. The thermal treatment at temperature below decomposition (380 °C) maintains the polymer structure, removing the side-products of the polymerization entrapped in the pores and improving the textural properties. On the other hand, the carbonization leads to a different material, enhancing both surface area and total pore volume—the textural properties of the final porous carbons are affected by the activation procedure and by the starting polymer. Different chemical activation methods and temperatures lead to different carbons with BET surface area ranging between 2318 and 2975 m2/g and pore volume up to 1.30 cc/g. The wise choice of the carbonization treatment allows the final textural properties to be finely tuned by increasing either the narrow pore fraction or the micro- and mesoporous volume. High pressure gas adsorption measurements of methane, hydrogen, and carbon dioxide of the most promising material are investigated, and the storage capacity for methane is measured and discussed.

Physicochemical Properties of Oxalic Acid-Modified Chitosan/Neem Leave Composites from Pessu River Crab Shell

2019 ◽  
Vol 17 (9) ◽  
Author(s):  
Oluwadayo Francis Asokogene ◽  
Muhammad Abbas Ahmad Zaini ◽  
Misau Muhammad Idris ◽  
Surajudeen Abdulsalam ◽  
Aliyu El-Nafaty Usman
Keyword(s):  
Methylene Blue ◽  
Oxalic Acid ◽  
Surface Area ◽  
Dye Adsorption ◽  
Textural Properties ◽  
Bet Surface Area ◽  
Blue Dye ◽  
Crab Shell ◽  
Sem Images ◽  
X Ray

Abstract This study was aimed to evaluate the characteristics of chitosan from Pessu river crab shell and its derivatives as prospective adsorbent. The synthesized chitosan (CH) was modified with 10 % (w/v) oxalic acid (CHOx), while the composites (CHOx-ANL1, CHOx-ANL2 and CHOx-ANL3) were designated according to the amount of activated neem leave (ANL). The materials were characterized by Fourier transform infrared (FTIR), energy-dispersive X-ray (EDAX), X-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET), thermal gravimetric (TGA) and methylene blue dye adsorption. The FTIR spectra of chitosan samples show the characteristics of primary and secondary amine/amide groups. The SEM images exhibit a tight, porous and fractured surface, which is covered with activated neem leave for the composites. The BET surface area of chitosan materials is in the increasing order of, CH < CHOx-ANL1 < CHOx-ANL2 < CHOx < CHOx-ANL3. CHOx-ANL3 displays a higher surface area of 389 m2/g, and 70.9 % mesoporosity. Despite its lower surface area of 258 m2/g (65.4 % mesoporosity), CHOx-ANL1 exhibits a greater methylene blue adsorption of 90.8 mg/g at dye concentration of 300 mg/L. The possible removal mechanisms include ionic interaction between dye molecules and functional groups, and surface adsorption due to the textural properties of chitosan samples. Chitosan from Pessu river crab shell and its derivatives are promising adsorbent candidate for dyes and heavy metals removal from water.

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