Studying the removal of CO2 on stratified ZnO prepared by hydro

2021 ◽  
Vol 10 (4) ◽  
pp. 69-74
Author(s):  
Minh Pham Quang ◽  
Chang-Ha Lee ◽  
Tuan Vu Anh
Keyword(s):  
Physicochemical Properties ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Pore Volume ◽  
Desorption Isotherm ◽  
Co2 Removal ◽  
Gas Composition ◽  
Thermogravimetric Method ◽  
Removal Experiments ◽  
Adsorption Desorption

In this study, ZnO was synthesized by the simple hydrothermal method. The physicochemical properties of the materials were characterized by SEM, XRD, N adsorption/desorption isotherm methods. The CO2 removal experiments were conducted using the thermogravimetric method (TGA). The material has a stratified structure, with a surface area of 24.4 m2/g and a pore volume of 0.280 cm3/g. The influences of temperature, ZnO morphology, and feed gas composition were studied. Besides, the durability and applicability of the material were evaluated through repeated regeneration.

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 The Internal Recycle Reactor Enhances Porous Calcium Silicate Hydrates to Recover Phosphorus from Aqueous Solutions

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Guan ◽  
Shichao Tian
Keyword(s):  
Surface Area ◽  
Pore Volume ◽  
Calcium Silicate ◽  
Ph Value ◽  
Optimal Operation ◽  
Phosphorus Recovery ◽  
Operation Conditions ◽  
Calcium Silicate Hydrates ◽  
Recycle Reactor ◽  
Adsorption Desorption

In this experiment, the porous calcium silicate hydrates (P-CSHs) were prepared via a hydrothermal method and then modified by polyethylene glycol (PEG). The modified P-CSHs combined with an internal recycle reactor could successfully recover the phosphorus from electroplating wastewater. The modified P-CSHs were characterized by X-ray diffraction (XRD), N2 adsorption-desorption isotherms, and Fourier transform infrared spectroscopy (FT-IR). After compared with different samples, the modified P-CSHs-PEG2000 sample had larger specific surface area of 87.48 m2/g and higher pore volume of 0.33 cm3/g, indicating a high capacity for phosphorus recovery. In the process of phosphorus recovery, the pH value of solution was increased to 9.5, which would enhance the recovery efficiency of phosphorus. The dissolution rate of Ca2+ from P-CSH-PEG2000 was fast, which was favorable for phosphorus precipitation and phosphorus recovery. The effects of initial concentration of phosphorus, P-CSHs-PEG2000 dosage, and stirring speed on phosphorus recovery were analyzed, so the optimal operation conditions for phosphorus recovery were obtained. The deposition was analyzed by XRD, N2 adsorption-desorption, and SEM techniques; it was indicated that the pore volume and surface area of the P-CSHs-PEG2000 were significantly reduced, and the deposition on the surface of P-CSHs-PEG2000 was hydroxyapatite.

scholarly journals Physicochemical and Technological Aspects of the Hydrothermal Modification of Complex Sorbents and Catalysts. Part I. Modification of Porous and Crystalline Structures

1997 ◽  
Vol 15 (3) ◽  
pp. 189-214 ◽  
Author(s):  
R. Leboda ◽  
B. Charmas ◽  
V.V. Sidorchuk
Keyword(s):  
Composite Materials ◽  
Physicochemical Properties ◽  
Specific Surface ◽  
Porous Structure ◽  
Hydrothermal Method ◽  
Ferric Oxide ◽  
Pore Volume ◽  
Structure Parameters ◽  
Mechanical Stirring ◽  
Hydrothermal Modification

This paper deals with the hydrothermal modification of the physicochemical properties of complex mineral sorbents and catalysts. The hydrothermal modification of alumina, magnesia, ferric oxide and zirconia/silica hydro- and xero-gels as well as other complex adsorbents obtained by the coprecipitation and mechanical stirring of suitable components is discussed. The paper deals with the following topics: (a) the physicochemical bases of the hydrothermal method; (b) methodological and technological problems of the hydrothermal treatment of adsorbents; (c) hydrothermal modification of porous structure parameters (specific surface area, pore volume and size); and (d) characteristics of the hydrothermal modification of the porous structure of multicomponent adsorbents and catalysts. In addition, the mechanism of the hydrothermal modification of the porous structure of composite materials is discussed.

Characterization of Titania Nanoparticles Synthesized by the Hydrothermal Method with Low Grade Mineral Precursors

2012 ◽  
Vol 21 ◽  
pp. 71-76 ◽  
Author(s):  
E.M. Mahdi ◽  
Mohd Hamdi Abdul Shukor ◽  
Yusoff M.S. Meor ◽  
Paulus Wilfred
Keyword(s):  
Crystallite Size ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Titania Nanoparticles ◽  
Low Grade ◽  
Synthetic Rutile ◽  
Chemical Reagents ◽  
20 Nm ◽  
Adsorption Desorption

The objective of this work is to utilize a low-grade synthetic rutile to produce high-grade titania nanoparticles. Due to the nature of the precursor, the hydrothermal method needs modification in order to accommodate the precursors and chemical reagents. The product will be characterized with the XRD (crystallite size and crystallinity), EDXRF (chemical composition), SEM (Morphology), N2 adsorption-desorption (Surface Area) and UV-Vis-NIR. Results revealed a crystallite size of less than 20 nm, a surface area of 186.8 m2/g, a morphology that is a combination of agglomeration and particles, and an optical band gap of 3.23 eV. It is concluded that synthetic rutile is a viable precursor to produce high quality titania nanoparticles.

scholarly journals Synthesis of micro-mesopores flowerlike γ-Al2O3 nano-architectures

2014 ◽  
Vol 79 (8) ◽  
pp. 1007-1017 ◽  
Author(s):  
Mozaffar Abdollahifar ◽  
Reza Zamani ◽  
Ehsan Beiygie ◽  
Hosain Nekouei
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Total Pore Volume ◽  
High Specific Surface Area ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Adsorption Desorption

The micro-mesopores flowerlike ?-Al2O3 nano-architectures have been synthesized by thermal decomposition method using the synthesized AlOOH (boehmite) as precursor. After calcination at 500?C for 5 h, the obtained flowerlike ?-Al2O3 has similar structure like the AlOOH precursor. X-ray diffraction (XRD), FTIR, TG, FESEM and TEM techniques were used to characterize morphology and structure of the synthesized samples. The specific surface area (BET), pore volume and pore-size distribution of the products were determined by N2 adsorption-desorption measurements. The flowerlike ?-Al2O3 showed BET high specific surface area 148 m2 g-1 with total pore volume 0.59 cm3 g-1.

scholarly journals The Role of the Aluminum Source on the Physicochemical Properties of γ-AlOOH Nanoparticles

2020 ◽  
Vol 39 (1) ◽  
pp. 89
Author(s):  
Rafael Romero Toledo ◽  
Luis M. Anaya Esparza ◽  
J. Merced Martínez Rosales
Keyword(s):  
Electron Microscopy ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
X Ray ◽  
Aluminum Salts ◽  
Adsorption Desorption

The effect on the physicochemical properties of aluminum salts on the synthesis of γ-AlOOH nanostructures has been investigated in detail using a hydrolysis-precipitation method. X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), were used to characterize the synthesized samples. The specific surface area, pore size distribution and pore diameter of the different γ-AlOOH structures were discussed by the N2 adsorption-desorption analysis. According to the results of the nanostructure, characterization revealed that for synthesized γ-AlOOH nanostructures from AlCl3 and Al(NO3)3, obvious XRD peaks corresponding to the bayerite phase are found indicating an impure γ-AlOOH phase. Furthermore, the nitrogen adsorption-desorption analysis indicated that the obtained γ-AlOOH nanoparticles from Al2(SO4)3 of technical grade (95.0 % of purity) and low cost, possess a high BET surface area of approximately 350 m2/g, compared to the obtained nanostructures from aluminum sources reactive grade, which was attributed to the presence of Mg (0.9 wt.%) in its nanostructure.

scholarly journals ALKALIZING AGENT INFLUENCE ON THE CeO2 CATALYST SYNTHESIS AND PROPERTIES

2016 ◽  
Vol 13 (25) ◽  
pp. 23-29
Author(s):  
Matheus José Cunha DE OLIVEIRA ◽  
Max Rocha QUIRINO ◽  
Magna Silmara Oliveira DE ARAÚJO ◽  
Oscar Borges MELO ◽  
Lucianna GAMA
Keyword(s):  
Fuel Cells ◽  
Hydrothermal Method ◽  
Surface Area ◽  
Pore Volume ◽  
Oxygen Sensors ◽  
Catalyst Synthesis ◽  
Synthesis Conditions ◽  
Uv Absorber ◽  
Microwave Hydrothermal ◽  
Microwave Hydrothermal Method

Cerium oxide is an important catalyst used in several reactions as electrolytes in fuel cells, UV absorber and oxygen sensors. The objective of the present work is CeO2 catalyst synthesis by microwave hydrothermal method and then evaluate the influence of NaOH, NH4OH and urea as alkalizing agents in the catalyst properties. The results showed that it was possible to obtain the monophasic catalyst only when using NaOH and NH4OH as precursors; the first presenting greater surface area (141.09 m2.g-1) and higher pore volume. It was concluded that using urea as alkalizing agent synthesis conditions were not sufficient for monophasic cerium production.

scholarly journals Effects of gaseous environments on physicochemical properties of thermally exfoliated graphene oxides for hydrogen storage: A comparative study

2021 ◽  
Author(s):  
Sohan Bir Singh ◽  
Mahuya De
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Storage ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Functional Groups ◽  
Layered Structure ◽  
Pore Volume ◽  
Average Pore Size ◽  
Average Pore ◽  
Exfoliated Graphene

Abstract The present study compared the effect of different gaseous environments on physicochemical properties and subsequent hydrogen storage ability of thermally exfoliated graphene oxide (EGO). The reducing, inert or oxidizing environments were generated using hydrogen, argon or air as the carrier gas, respectively. The structure of thermally exfoliated graphene oxide depended on the type of gaseous environment. The EGO prepared in presence of Air showed the fluffiest layered structure having highest surface area. The surface area order was EGO(Air) (268 m2/g) > EGO(H2) (248 m2/g) > EGO(Ar) (155 m2/g). The average pore sizes of EGO(Air) and EGO(H2) were 2.9 and 2.8 nm, with pore volumes of 1.2 and 1.6 cm3/g, respectively. The average pore size for EGO(Ar) was highest at 4.1 nm, associated with presence of larger void space and lowest total pore volume of 1.0 cm3/g. Thus, presence of oxidative or reducing atmosphere seemed to be more conducive to exfoliation of layers by gradual removal of functional groups. The inert atmosphere of argon caused severe thermal separation of layers and functional groups, adversely affecting the layered structure as observed. The EGO(Air) also showed highest O/C ratio suggesting presence of significant amount of oxygen–containing functional groups on the surface. The hydrogen uptake order at 77 K and 30 bar was: EGO (Air) 3.34 wt.% > EGO (H2) 3.12 wt.% > EGO (Ar) 2.2 wt.%. The highest uptake of EGO(Air) might have resulted from highest surface area, highest O/C ratio and presence of considerable pore volume.

scholarly journals ACID ACTIVATION OF PRRENJAS CLAY MINERAL

2018 ◽  
Vol 4 (7) ◽  
Author(s):  
Altin Mele ◽  
Krenaida Taraj ◽  
Arjan Korpa
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Clay Mineral ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Gas Adsorption ◽  
Exchange Capacity ◽  
Acid Activation ◽  
Composition Structure ◽  
Adsorption Desorption

Prrenjas clay mineral is found in southeast Albania and has a high content on bentonite. Theinfluence of the sulphuric acid activation on the composition, structure and surface properties ofPrrenjas clay mineral is investigated in this study by means of elemental chemical analysis, X-RayDiffractometry, IR Spectroscopy and gas adsorption-desorption measurement. H2SO4concentrations of 0.143 M, 0.232 M, 0.371 M, 0.537 M, 0.734 M, 0.927 M and 1.456 M were used inthe treatment of samples. The treatment by increasing the acid concentration brings the leaching ofAl3+, Fe2+, Mg2+ from the clay structure. The specific surface area and the pore volume of the claysamples increases respectively from 83 m2/g and 0.069 cm3/g for the untreated clay to 420 m2/g and0.384 cm3/g for the clay mineral treated with 1.456 M H2SO4 solution. New mesopores were createdduring the acid activation mainly in the range of 2 – 8 nm. For the samples treated with 0.927 Mand 1.456 M solutions the increase in specific surface area and pore volume is very high. Thecationic exchange capacity decreases steadily with the concentration of H2SO4 used for thetreatment.

scholarly journals TEXTURAL AND MORPHOLOGICAL CHARACTERIZATION OF COPPER(II)-EXCHANGED ROMANIAN CALCIUM BENTONITE

2017 ◽  
Vol 20 (3) ◽  
Author(s):  
ANA-MARIA GEORGESCU ◽  
GHEORGHE BRABIE ◽  
ILEANA DENISA NISTOR ◽  
CLAUDE PENOT ◽  
FRANÇOISE NARDOU
Keyword(s):  
Ion Exchange ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Nitrogen Adsorption ◽  
Desorption Isotherm ◽  
Scanning Electron Micrographs ◽  
Adsorption Desorption ◽  
Calcium Bentonite ◽  
Scanning Electron

<p>Romanian calcium bentonite was modified by copper(II) ion-exchange, by varying the copper precursors (chloride, sulphate) and synthesis parameters (pH, temperature, time). The quantification of the Cu(II) ions was carried out by atomic absorption spectrophotometer. The modified bentonites were characterized by textural analysis (specific surface area by the Brunauer-Emmett-Teller method (BET) and by nitrogen adsorption/desorption isotherm), structural composition (X-ray diffraction (XRD)) and morphological analysis (scanning electron microscopy (SEM)). Analysis of the nitrogen adsorption/desorption isotherm shows that ion exchanged bentonites, not only contain mesopores, but micropores in larger quantities too. The values of the specific surface area increased by about 20 m<sup>2</sup>/g compared with raw bentonite, but the interlamellar distance values do not vary substantially. Scanning electron micrographs were acquired to demonstrate changes in the texture of the clay before and after ion exchange.</p>

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