scholarly journals Effect of Catalytic Gasification of Active Carbon from Plum Stones on its Mesoporous Structure

1993 ◽  
Vol 10 (1-4) ◽  
pp. 221-240 ◽  
Author(s):  
R. Leboda ◽  
W. Grzegorczyk ◽  
A. Lodyga ◽  
A. Dabrowski
Keyword(s):  
Active Carbon ◽  
Carbon Adsorbent ◽  
Carbonaceous Material ◽  
Mesoporous Structure ◽  
Carbon Adsorbents ◽  
Porous Structures ◽  
X Ray Diffraction ◽  
Catalytic Gasification ◽  
Adsorption Desorption ◽  
Kinetics Of

The possibilities of the development of a mesoporous structure during gasification of carbonaceous material with water vapour in the presence of a calcium(II) catalyst are demonstrated. Investigations have been carried out on active carbon prepared from plum stones. For comparison, the same experiments in the absence of the catalyst were also made. The characteristics of the micro- and meso-porous structures of the adsorbents have been determined from the adsorption–desorption isotherms of nitrogen. The data have been submitted to treatment from the BET, Harkins–Jura, Sing as well as Derjaguin, Broeckhoff, de Boer and Dubinin equations. The texture of the adsorbent particles has been studied by means of scanning electron microscopy. The kinetics of gasification of the carbon adsorbent in the presence and absence of catalyst has also been studied. In addition, samples of the prepared carbon adsorbents were examined by X-ray diffraction.

scholarly journals Adsorption of malic acid at the hydroxyapatite/aqueous NaCl solution interface

2021 ◽  
Author(s):  
Władysław Janusz ◽  
Ewa Skwarek
Keyword(s):  
Zeta Potential ◽  
Malic Acid ◽  
Particle Sizes ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Radioisotope Method ◽  
X Ray ◽  
Solution Interface ◽  
Adsorption Desorption ◽  
Kinetics Of

AbstractThe aim of the study was the basic incidence on the phenomenon of adsorption that occurs at the hydroxyapatite/malic acid interface, leading to a change in the surface properties of hydroxyapatite, Analytical methods used in the research: X-ray diffraction (XRD) as well as by the, adsorption–desorption of nitrogen (ASAP), potentiometric titration. The specific adsorption of malic acid ions at the hydroxyapatite interface was investigated by means of the radioisotope method. The zeta potential of hydroxyapatite dispersions was determined by electrophoresis with Zetasizer Nano ZS90 by Malvern. The particle sizes of hydroxyapatite samples were analyzed using Masteriszer 2000 Malvern. Studies on the kinetics of malic acid on hydroxyapatite from a solution with an initial concentration of 1 mmol/dm3 have shown that the adsorption process is initially fast, followed by a slow adsorption step. An increase in the pH of the solution causes a decrease in the malic acid adsorption as a result of competition with hydroxyl ions. The presence of adsorbed malic acid was confirmed by the FTIR measurements. The effect of malic acid adsorption on the zeta potential and particle size distribution of hydroxyapatite in the NaCl solution was investigated.

Synthesis and Characterization of Polythiophene / SBA-15 Composite

2014 ◽  
Vol 968 ◽  
pp. 49-52
Author(s):  
Qin Qin Hou
Keyword(s):  
Thermogravimetric Analysis ◽  
Oxidative Polymerization ◽  
Mesoporous Structure ◽  
Synthesis And Characterization ◽  
Scan Electron Micrographs ◽  
X Ray Diffraction ◽  
Channel System ◽  
X Ray ◽  
Adsorption Desorption

A new nanocomposite, semiconducting polythiophene (PT) confined in mesoporous silica (SBA-15) was synthesized. PT was formed in the pores of SBA-15 by subsequent oxidative polymerization with FeCl3. Different techniques were used to characterize the nanocomposite formation. X-ray diffraction (XRD) and N2 adsorption/desorption analysis showed that the nanocomposite possesses mesoporous structure, and the residual pore volume of nanocomposite was significantly lower than that of pure empty SBA-15. Scan electron micrographs confirmed the presence of polythiophene inside pore channels of the host, and thermogravimetric analysis proved confinement effect in the channel system.

scholarly journals Hydrogen-rich syngas production via catalytic gasification of biomass using Ni/Zr-MOF catalyst

BioResources ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1716-1731 ◽  
Author(s):  
Shuang Shang ◽  
Zhenhua Qin ◽  
Kui Lan ◽  
Yan Wang ◽  
Juanjuan Zhang ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Mesoporous Structure ◽  
Biomass Gasification ◽  
Precipitation Method ◽  
High Catalytic Activity ◽  
X Ray Diffraction ◽  
Catalytic Gasification ◽  
Syngas Production ◽  
Metal Organic ◽  
H2 Yield

A Ni/Zr-MOF catalyst supported on Zr-metal organic framework (Zr-MOF) was prepared by a homogeneous precipitation method and was used in the co-gasification of wet sludge and straw. The Ni/Zr-MOF catalyst was characterized via thermogravimetric, X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry, and Brunauer-Emmett-Teller analyses. The experimental results illustrated that the Zr-MOF crystals were an octahedral structure with a specific surface area of 806 m2/g, and had mesoporous structure. Nickel was uniformly dispersed on the surface of the catalyst, and most of the Ni/Zr-MOF crystals maintained an octahedral morphology. Compared with non-catalyst biomass gasification, the H2 yield increased from 0.39 mol/kg to 11.87 mol/kg using the Ni/Zr-MOF catalyst at 500 °C. After 10 instances of reuse, the H2 yield was still as high as 10.11 mol/kg. The Ni/Zr-MOF catalyst exhibited high catalytic activity and stability for biomass gasification at low-temperature.

scholarly journals The adsorption study of Royal Blue Tiafix and Black Tiassolan dyes using bone char as adsorbent

2018 ◽  
Vol 36 (3-4) ◽  
pp. 1178-1198 ◽  
Author(s):  
Rowander A Moura ◽  
Araceli A Seolatto ◽  
Maria E de Oliveira Ferreira ◽  
Fernanda F Freitas
Keyword(s):  
Second Order ◽  
Bone Char ◽  
X Ray Diffraction ◽  
First Order ◽  
Freundlich Isotherms ◽  
Pseudo Second Order ◽  
Dyes Adsorption ◽  
Adsorption Desorption ◽  
Full Factorial ◽  
Kinetics Of

In this study, the potential of bone char for Royal Blue Tiafix and Black Tiassolan dyes adsorption from aqueous solutions was evaluated. The adsorbent was characterized physically and chemically by adsorption/desorption of N2 at 77 K, scanning electron microscopy, X-ray diffraction, and infrared spectroscopy. The equilibrium adsorption results for bone char can be successfully modeled by the Langmuir and Freundlich isotherms. Pseudo-first-order and pseudo-second-order models were used to describe the kinetic data and rate constants were evaluated. Kinetics of each dye was found to follow pseudo-second-order rate kinetic model, with great correlation (higher than 0.99). In order to reduce the number of experiments to achieve better dye removal efficiency, a 2³ full factorial design with three central points and six axial points was applied in the equilibrium experiments. The variables analyzed were agitation, temperature, and pH.

scholarly journals Novel Route to Obtain Carbon Self-Doped TiO2 Mesoporous Nanoparticles as Efficient Photocatalysts for Environmental Remediation Processes under Visible Light

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3349 ◽  
Author(s):  
Pablo A. Ochoa Rodríguez ◽  
Tamara B. Benzaquén ◽  
Gina A. Pecchi ◽  
Sandra G. Casuscelli ◽  
Verónica R. Elías ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Environmental Remediation ◽  
Synthesis Method ◽  
Mesoporous Structure ◽  
Acid Orange 7 ◽  
X Ray Diffraction ◽  
Visible Radiation ◽  
X Ray ◽  
Transmission Electron ◽  
Adsorption Desorption

Titanium dioxide materials were synthesized using two different methods. The samples were characterized by X-ray diffraction (XRD), UV–Visible diffusion reflectance spectroscopy (UV-Vis DR), Raman spectroscopy, N2 adsorption/desorption, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron spectroscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Although both kind of materials were found to have mesoporous structure and anatase crystalline phase, one of them was obtained from a synthesis method that does not involve the use of surfactants, and therefore, does not require calcination at high temperatures. This implies that the synthesized solid was self-doped with carbon species, coming only from the same source used for titanium. Then, the relationship between the presence of these species, the final calcination temperature, and the photocatalytic activity of the solids was studied in terms of the degradation and mineralization of an Acid Orange 7 aqueous solution, under visible radiation. A photosensitizing effect caused by the non-metal presence, that allows the solid to extend its absorption range, was found. Hence, a novel route to prepare C-modified photoactive mesoporous TiO2, simpler and cheaper, where neither a template nor an external carbon source is used, could be performed.

Synthesis and Characterization of Nanocrystalline CeO2

2006 ◽  
Vol 306-308 ◽  
pp. 1103-1108
Author(s):  
Abdul Hadi ◽  
Iskandar Idris Yaacob
Keyword(s):  
Fine Particles ◽  
Gas Adsorption ◽  
Mesoporous Structure ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Face Centered ◽  
Adsorption Desorption

Nanocrystalline CeO2 has been synthesized at room temperature using water-in-oil (w/o) microemulsion technique. The structure and properties of the nanocrystalline CeO2 were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and gas adsorption desorption measurement. XRD results showed the synthesized CeO2 has a face centered cubic structure with crystallite size of about 5.2 nm. TEM observation also indicated the presence of nanometer sized particles of CeO2. Coarser particles were also observed due to agglomeration. Gas adsorption desorption isotherms showed the behavior of fine particles with mesoporous structure.

Deactivation Behavior of CuXCe1-XO2-X/SBA-15/Cordierite Monolithic Catalysts for Catalytic Combustion of CO

2012 ◽  
Vol 550-553 ◽  
pp. 383-387 ◽  
Author(s):  
Fu Zhen Zhao ◽  
Wen Qiang Liang ◽  
Sheng Bin Ling ◽  
Yu Qing Wu ◽  
Ai Qing Zhang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Combustion ◽  
Mesoporous Structure ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Monolithic Catalysts ◽  
Adsorption Desorption

A series of CuxCe1-xO2-x/SBA-15/cordierite (x = 0-1) catalysts were prepared. The activity of the catalysts for CO combustion was evaluated. The catalysts were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, and X-ray photoelectron spectroscopy (XPS). Deactivation behavior of the catalysts for the catalytic combustion of CO was investigated. The results show that all of the catalysts retained the SBA-15 mesoporous structure. It is proposed that deactivation of the catalysts is associated with the increase of the Cu+ and the decrease of the Cu2+ in the catalysts.

Rice Straw and Rice Straw Ash as Precursor for Synthesis of Mesoporous Molecular Sieves MCM-41

2012 ◽  
Vol 550-553 ◽  
pp. 1391-1394
Author(s):  
Xiao Hong Tang ◽  
Bao Jun Li ◽  
Cheng Wei Li
Keyword(s):  
Rice Straw ◽  
Molecular Sieves ◽  
Mesoporous Structure ◽  
Mesoporous Molecular Sieves ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Straw Ash ◽  
Mcm 41

In this paper, rice straw (RS) and rice straw ash (RSA) were employed to synthesize mesoporous molecular sieves MCM-41 in an open-vessel. The structure of as-synthesized MCM-41 was characterized by X-ray diffraction (XRD) pattern, Fourier transform infrared (FT–IR) spectrum, NH3-Temperature Programmed Desorption (TPD), and N2 adsorption-desorption isotherms. RS-MCM-41 and RSA-MCM-41 possess the same typical hexagonal mesoporous structure with high long-range order and crystalline degree as those of MCM-41 from water glass (SDS-MCM-41).

scholarly journals Catalytic Performance of TiO2–Carbon Mesoporous-Derived from Fish Bones in Styrene Oxidation with Aqueous Hydrogen Peroxide as an Oxidant

2021 ◽  
Vol 16 (1) ◽  
pp. 88-96
Author(s):  
Mukhamad Nurhadi ◽  
Ratna Kusumawardani ◽  
Teguh Wirawan ◽  
Sumari Sumari ◽  
Sin Yuan Lai ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Styrene Oxidation ◽  
Aqueous Hydrogen Peroxide ◽  
X Ray ◽  
Fish Bones ◽  
Adsorption Desorption ◽  
Kinetics Of

The catalytic performance of titania-supported carbon mesoporous-derived from fish bones (TiO2/CFB) has been investigated in styrene oxidation with aqueous H2O2. The preparation steps of (TiO2/CFB) catalyst involved the carbonization of fish bones powder at 500 °C for 2 h. followed by impregnation of titania using titanium(IV) isopropoxide (500 µmol) precursor, and calcined at 350 °C for 3 h. The physical properties of the adsorbents were characterized using Fourier transform infrared, X-ray diffraction (XRD), Scanning electron microscopy with energy dispersive X-ray (SEM-EDX), and nitrogen adsorption-desorption studies. The catalytic test was carried out using styrene oxidation with H2O2 as an oxidant at room temperature for 24 h. Its catalytic activity was compared with Fe2O3/CFB, CuO/CFB, TiO2, and CFB catalysts. It is demonstrated that the catalytic activity of TiO2/CFB catalyst has the highest compared to Fe2O3/CFB, CuO/CFB, TiO2, and CFB catalysts in the oxidation of styrene with styrene conversion ~23% and benzaldehyde selectivity ~90%. Kinetics of TiO2/CFB catalyzed oxidation of styrene has been investigated and mechanism for oxidation of styrene has been proposed. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA   License (https://creativecommons.org/licenses/by-sa/4.0). 

Adsorption of noble gases on the carbon adsorbents supersorbon HS and Jado

1983 ◽  
Vol 48 (3) ◽  
pp. 819-826 ◽  
Author(s):  
Ludmila Wilhelmová ◽  
František Cejnar
Keyword(s):  
Gas Chromatography ◽  
Active Carbon ◽  
Noble Gases ◽  
Carbon Adsorbent ◽  
Adsorption Properties ◽  
Carbon Adsorbents ◽  
Adsorption Behaviour ◽  
Practical Application ◽  
Heats Of Adsorption ◽  
Temperature Range

The isotherms, isosters and heats of adsorption of argon, krypton and xenon were measured on the active carbon Supersorbon HS and the carbon adsorbent Jado LD 1191 - in a temperature range 298-473 K, using gas chromatography. Differences were observed in the adsorption behaviour of both types of adsorbents - which showed especially on the nonlinearity of adsorption isosters of all gases studied with the Jado LD 1191 adsorbent. It was found that both types of adsorbents possess good adsorption properties, which can be - for Supersorb HS - utilized in the beds of the delaying lines of radioactive noble gases. The practical application of the Jado LD 1191 adsorbent for the same purposes is limited by the presence of inactive teflon support in the structure of this adsorbent.

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