Synthesis And Characterization Of Pillared Acid-Activated Montmorillonites

1991 ◽  
Vol 233 ◽  
Author(s):  
Robert Mokaya ◽  
William Jones ◽  
Mavis E. Whittle ◽  
Mary E. Davies
Keyword(s):  
Cation Exchange ◽  
Adsorption Capacity ◽  
Surface Acidity ◽  
Xrd Analysis ◽  
Pillared Clays ◽  
Synthesis And Characterization ◽  
Drying Method ◽  
Surface Areas ◽  
Powder Xrd Analysis

ABSTRACTPolymeric hydroxy-Al cations were introduced into the interlayer of acid-activated montmorillonites by cation exchange. The resulting pillared materials possessed layer spacings of 18 – 20 Å, surface areas between 250 – 320 m2/g, pore volumes in the range 0.3 – 0.38 cc/g and pore diameters in the range 32 – 40 Å depending on preparation procedures (i.e pillaring temperature and drying method). Powder XRD analysis indicated that the pillars formed were stable to temperatures above 500 °C. The surface acidity of these type of pillared clays was higher than that of pillared non-activated clays. Preliminary studies on their adsorption capacity for chlorophyll showed that they were superior to pillared non-activated clays.

Synthesis and characterization of pure silica zeolite beta obtained by an aging–drying method

2011 ◽  
Vol 143 (1) ◽  
pp. 196-205 ◽  
Author(s):  
Farlán Taborda ◽  
Tom Willhammar ◽  
Zhengyang Wang ◽  
Consuelo Montes ◽  
Xiaodong Zou
Keyword(s):  
Zeolite Beta ◽  
Synthesis And Characterization ◽  
Drying Method ◽  
Pure Silica

Synthesis and characterization of pecan nutshell-based adsorbent with high specific area and high methylene blue adsorption capacity

2019 ◽  
Vol 276 ◽  
pp. 570-576 ◽  
Author(s):  
Hugo H.C. Lima ◽  
Rogério S. Maniezzo ◽  
Maria E.G. Llop ◽  
Vincente L. Kupfer ◽  
Pedro A. Arroyo ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Specific Area ◽  
Synthesis And Characterization ◽  
Methylene Blue Adsorption ◽  
Pecan Nutshell ◽  
High Specific Area

Synthesis and characterization of novel cation exchange adsorbent for the treatment of real samples for metal ions

2012 ◽  
Vol 200-202 ◽  
pp. 426-432 ◽  
Author(s):  
S.A. Nabi ◽  
A.S. Raeissi ◽  
Mohammad Shahadat ◽  
Rani Bushra ◽  
Amjad Mumtaz Khan
Keyword(s):  
Metal Ions ◽  
Cation Exchange ◽  
Synthesis And Characterization ◽  
Real Samples

scholarly journals Adsorption of strontium on different sodium-enriched bentonites

2017 ◽  
Vol 82 (4) ◽  
pp. 449-463 ◽  
Author(s):  
Sanja Marinovic ◽  
Marija Ajdukovic ◽  
Natasa Jovic-Jovicic ◽  
Tihana Mudrinic ◽  
Bojana Nedic-Vasiljevic ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Adsorption Capacity ◽  
Textural Properties ◽  
X Ray Diffraction ◽  
Order Model ◽  
Surface Areas ◽  
Alkaline Conditions ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ph Range

Bentonites from three different deposits (Wyoming, TX, USA and Bogovina, Serbia) with similar cation exchange capacities were sodium enriched and tested as adsorbents for Sr2+ in aqueous solutions. X-Ray diffraction analysis confirmed successful Na-exchange. The textural properties of the bentonite samples were determined using low-temperature the nitrogen physisorption method. Significant differences in the textural properties between the different sodium enriched bentonites were found. Adsorption was investigated with respect to adsorbent dosage, pH, contact time and the initial concentration of Sr2+. The adsorption capacity increased with pH. In the pH range from 4.0?8.5, the amount of adsorbed Sr2+ was almost constant but 2?3 times smaller than at pH ?11. Further experiments were performed at the unadjusted pH since extreme alkaline conditions are environmentally hostile and inapplicable in real systems. The adsorption capacity of all the investigated adsorbents toward Sr2+ was similar under the investigated conditions, regardless of significant differences in the specific surface areas. It was shown and confirmed by the Dubinin?Radushkevich model that the cation exchange mechanism was the dominant mechanism of Sr2+ adsorption. Their developed microporous structures contributed to the Sr2+ adsorption process. The adsorption kinetics obeyed the pseudo-second-order model. The isotherm data were best fitted with the Langmuir isotherm model.

Synthesis and Characterization of Aerogel-derived Cation-substituted Hexaaluminates

1996 ◽  
Vol 457 ◽  
Author(s):  
Lin-chiuan Yan ◽  
Levi T. Thompson
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Catalytic Combustion ◽  
High Surface ◽  
High Surface Area ◽  
Synthesis And Characterization ◽  
New Methods ◽  
Surface Areas ◽  
Different Characteristics

ABSTRACTNew methods have been developed for the synthesis of high surface area cation-substituted hexaaluminates. These materials were prepared by calcining high temperature (ethanol extraction) or low temperature (CO2 extraction) aerogels at temperatures up to 1600°C. Cation-substituted hexaaluminates have emerged as promising catalysts for use in high temperature catalytic combustion. In comparing unsubstituted and cation-substituted hexaaluminates, we found that the phase transformations were much cleaner for the cation-substituted materials. BaCO3 and BaAl2O4 were intermediates during transformation of the unsubstituted materials, while the cation-substituted materials transformed directly from an amorphous phase to crystalline hexaaluminate. Moreover, the presence of substitution cations caused the transformation to occur at lower temperatures. Mn seems to be a better substitution cation than Co since the Mn-substituted materials exhibited higher surface areas and better heat resistances than the Co-substituted materials. The low temperature aerogel-derived materials possessed quite different characteristics from the high temperature aerogel-derived materials. For example, phase transformation pathways were different.

scholarly journals Synthesis and Characterization of Silica Aerogel from Rice Husk with Ambient Pressure Drying Method

2020 ◽  
Vol 1535 ◽  
pp. 012049
Author(s):  
Nor Fadilah Mohamad ◽  
Noor Hidayu Abdul Rani ◽  
Omar Syah Jehan Elham ◽  
Siti Hajar Anaziah Muhamad ◽  
Siti Afifah Muda ◽  
...  
Keyword(s):  
Rice Husk ◽  
Silica Aerogel ◽  
Ambient Pressure ◽  
Ambient Pressure Drying ◽  
Synthesis And Characterization ◽  
Drying Method

Synthesis and Characterization of Nanoscale CeO2 Catalyst for deNOx

2005 ◽  
Vol 23 ◽  
pp. 95-98 ◽  
Author(s):  
S. Kawi ◽  
Y.P. Tang ◽  
K. Hidajat ◽  
L.E. Yu
Keyword(s):  
Water Vapor ◽  
Catalytic Reduction ◽  
Precipitation Method ◽  
Synthesis And Characterization ◽  
In Situ Xrd ◽  
Surface Areas ◽  
Rich Condition ◽  
The One

Hydrothermal and precipitation methods have been applied to synthesize nanoscale CeO2 catalysts for selective catalytic reduction of NO with hydrocarbon under oxygen-rich condition. The former procedure has the advantage of enhancing the hydrothermal stability of nanomaterial. BET results show that their surface areas are about 30-80 m2/g. Based on TEM results, hydrothermally prepared CeO2 shows very uniform grain shaped particles with size around 10-20 nanometers. Its thermal stability up to 1200°C has been confirmed by in-situ XRD. Furthermore, deNOx reaction with propene as reducing agent in the presence of 5% oxygen has been carried out to compare catalysts prepared by the above two methods. Results show that hydrothermally prepared catalyst is more active than the one prepared by precipitation method. The latter one lost half of its activity in the presence of 5% water vapor, while the former one could stand up to 10% water vapor in the gas mixture without losing much activity.

ChemInform Abstract: Synthesis and Characterization of Pillared Clays Containing Both Si and Al Pillars.

ChemInform ◽  
2010 ◽  
Vol 26 (42) ◽  
pp. no-no
Author(s):  
G. FETTER ◽  
D. TICHIT ◽  
L. C. DE MENORVAL ◽  
F. FIGUERAS
Keyword(s):  
Pillared Clays ◽  
Synthesis And Characterization
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