Effect of synthesis parameters on the crystallinity of EU-1 zeolite for the m-xylene isomerization reaction

A specific one-step mild dealumination of ZSM-5 is reported that increases significantly para xylene selectivity and ethyl benzene conversion in the xylene isomerization reaction of xylene mixtures/ethyl benzene feeds at industrial conditions.

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Influence of lanthanum concentration on acid and catalytic properties of H-pentasil in the μ-xylene isomerization reaction

Russian Journal of Applied Chemistry ◽

10.1134/s1070427209050334 ◽

2009 ◽

Vol 82 (5) ◽

pp. 918-919

Author(s):

E. I. Akhmedov ◽

I. A. Aliev ◽

Kh. M. Azmamedova ◽

F. Sh. Kerimli ◽

S. E. Mamedov

Keyword(s):

Catalytic Properties ◽

Isomerization Reaction ◽

Xylene Isomerization

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Influence of synthesis parameters on barium titanate structural properties obtained by microwave assisted solvothermal method.

10.26678/abcm.cobem2019.cob2019-0437 ◽

2019 ◽

Author(s):

Amanda Pereira dos Santos da Costa ◽

YURI VINICIUS BRUSCHI DE SANTANA ◽

Ana Paula de Moura

Keyword(s):

Barium Titanate ◽

Structural Properties ◽

Solvothermal Method ◽

Microwave Assisted ◽

Synthesis Parameters

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Aromatic Transformation in Fluidized Bed Reactors

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20081061 ◽

2008 ◽

Vol 73 (8-9) ◽

pp. 1061-1088

Author(s):

Sule Rabiu ◽

Sulaiman Al-Khattaf

Keyword(s):

Fluidized Bed ◽

The Other ◽

Fluidized Bed Reactors ◽

Y Zeolite ◽

Y Zeolites ◽

Toluene Disproportionation ◽

Xylene Isomerization ◽

Toluene Methylation ◽

Toluene Conversion ◽

Medium Acidity

In this work three important aromatic transformations, namely: toluene disproportionation, toluene methylation and m-xylene isomerization, were investigated in a riser simulator which closely mimics the operation of commercial fluidized bed reactors. The transformations were studied over a ZSM-5 based catalyst with medium acidity of 0.23 mmol/g and a series of Y zeolites of acidities between 0.55 and 0.03 mmol/g. For pure toluene feed, it was observed that conversion over the ZSM-5 based catalyst and the weakly acidic Y zeolite (USY-1) was very low. However, with the highly acidic Y zeolite (H-Y), significant toluene conversion was observed with paring reaction more prominent than disproportionation. On the other hand, when toluene was alkylated with methanol, higher toluene conversions were achieved over both the ZSM-5 based and the weakly acidic USY-1 catalysts as compared to when pure toluene feed was used. In addition, p-xylene/o-xylene (P/O) ratios higher than the equilibrium values were obtained in the reaction product over both catalysts. Finally, for m-xylene isomerization it was found that m-xylene conversion increased initially as the acidity of the catalyst increased up to 0.1 mmol/g beyond which any further increase in acidity resulted in a slight decrease in the m-xylene conversion.

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A critical review of synthesis parameters affecting the properties of zinc oxide nanoparticle and its application in wastewater treatment

Applied Water Science ◽

10.1007/s13201-021-01370-z ◽

2021 ◽

Vol 11 (2) ◽

Author(s):

E. Y. Shaba ◽

J. O. Jacob ◽

J. O. Tijani ◽

M. A. T. Suleiman

Keyword(s):

Zinc Oxide ◽

Metal Oxides ◽

Zinc Oxide Nanoparticles ◽

Textural Properties ◽

Oxide Nanoparticles ◽

Zinc Oxide Nanoparticle ◽

Synthesis Parameters ◽

Metal Precursors ◽

Removal Of Heavy Metals ◽

Oxide Nanoparticle

AbstractIn this era, nanotechnology is gaining enormous popularity due to its ability to reduce metals, metalloids and metal oxides into their nanosize, which essentially alter their physical, chemical, and optical properties. Zinc oxide nanoparticle is one of the most important semiconductor metal oxides with diverse applications in the field of material science. However, several factors, such as pH of the reaction mixture, calcination temperature, reaction time, stirring speed, nature of capping agents, and concentration of metal precursors, greatly affect the properties of the zinc oxide nanoparticles and their applications. This review focuses on the influence of the synthesis parameters on the morphology, mineralogical phase, textural properties, microstructures, and size of the zinc oxide nanoparticles. In addition, the review also examined the application of zinc oxides as nanoadsorbent for the removal of heavy metals from wastewater.

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Eco-Friendly Colloidal Aqueous Sol-Gel Process for TiO2 Synthesis: The Peptization Method to Obtain Crystalline and Photoactive Materials at Low Temperature

Catalysts ◽

10.3390/catal11070768 ◽

2021 ◽

Vol 11 (7) ◽

pp. 768

Author(s):

Julien G. Mahy ◽

Louise Lejeune ◽

Tommy Haynes ◽

Stéphanie D. Lambert ◽

Raphael Henrique Marques Marcilli ◽

...

Keyword(s):

Organic Pollutant ◽

Sol Gel ◽

Synthesis Method ◽

Specific Treatment ◽

High Specific Surface Area ◽

Crystalline Phases ◽

Tio2 Photocatalysts ◽

Tio2 Anatase ◽

Synthesis Parameters ◽

Calcination Step

This work reviews an eco-friendly process for producing TiO2 via colloidal aqueous sol–gel synthesis, resulting in crystalline materials without a calcination step. Three types of colloidal aqueous TiO2 are reviewed: the as-synthesized type obtained directly after synthesis, without any specific treatment; the calcined, obtained after a subsequent calcination step; and the hydrothermal, obtained after a specific autoclave treatment. This eco-friendly process is based on the hydrolysis of a Ti precursor in excess of water, followed by the peptization of the precipitated TiO2. Compared to classical TiO2 synthesis, this method results in crystalline TiO2 nanoparticles without any thermal treatment and uses only small amounts of organic chemicals. Depending on the synthesis parameters, the three crystalline phases of TiO2 (anatase, brookite, and rutile) can be obtained. The morphology of the nanoparticles can also be tailored by the synthesis parameters. The most important parameter is the peptizing agent. Indeed, depending on its acidic or basic character and also on its amount, it can modulate the crystallinity and morphology of TiO2. Colloidal aqueous TiO2 photocatalysts are mainly being used in various photocatalytic reactions for organic pollutant degradation. The as-synthesized materials seem to have equivalent photocatalytic efficiency to the photocatalysts post-treated with thermal treatments and the commercial Evonik Aeroxide P25, which is produced by a high-temperature process. Indeed, as-prepared, the TiO2 photocatalysts present a high specific surface area and crystalline phases. Emerging applications are also referenced, such as elaborating catalysts for fuel cells, nanocomposite drug delivery systems, or the inkjet printing of microstructures. Only a few works have explored these new properties, giving a lot of potential avenues for studying this eco-friendly TiO2 synthesis method for innovative implementations.

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