A COMPARISON OF THE X-RAY DIFFRACTION AND NITROGEN ADSORPTION SURFACE AREAS OF CARBON BLACKS AND CHARCOALS

1948 ◽  
Vol 26a (4) ◽  
pp. 236-242 ◽  
Author(s):  
J. C. Arnell ◽  
W. M. Barss
Keyword(s):  
Carbonaceous Material ◽  
Nitrogen Adsorption ◽  
Activation Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Blacks ◽  
Surface Areas ◽  
Crystallite Surface ◽  
Adsorption Surface ◽  
Order Of Magnitude

The surface areas, as determined from X-ray diffraction and low temperature nitrogen adsorption data, were compared for a number of carbon blacks and activated charcoals. Comparative data were also obtained on samples of charcoal at various stages of activation and after calcination. The X-ray diffraction data indicated that all the samples examined were composed of small graphitelike crystallites of the same order of magnitude, which had specific surfaces of about 2500 to 3000 sq. m. per cc. The nitrogen adsorption surface of a highly activated charcoal was found to be about equal to the X-ray surface. It is suggested that the crystallite surface represents the potential adsorption surface of a carbonaceous material and, providing that crystal growth does not occur during activation, the activation process makes these surfaces available to external adsorbate.

Structural and surface aspects of thermally treated copper aluminium mixed hydroxides

1991 ◽  
Vol 69 (10) ◽  
pp. 1511-1515 ◽  
Author(s):  
Awad I. Ahmed ◽  
S. E. Samra ◽  
S. A. El-Hakam
Keyword(s):  
Pore Structure ◽  
Copper Content ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Phase Changes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Structure Surface ◽  
Adsorption Desorption

CuO–Al2O3 catalysts containing various amounts of copper oxide have been prepared by precipitation. The phase changes were studied by X-ray diffraction. The results obtained revealed that the thermal treatment of solid CuO–Al2O3 at 700 °C produced only crystalline CuO. Heating to 900 °C led to the formation of copper alumina spinel together with unreacted CuO and γ-Al2O3. The spinel content was found to increase with increasing copper content. Nitrogen adsorption–desorption isotherms on the calcined samples have been measured. Surface areas have been calculated and the pore structure analysed. The textural properties of the system were found to depend on both the copper content and the calcination temperature. Key words: CuO, Al2O3 catalysts, structure, surface area, pore structure.

Active Magnesia. III. X-ray versus Nitrogen Adsorption Surface Areas.

1947 ◽  
Vol 51 (3) ◽  
pp. 763-767 ◽  
Author(s):  
A. C. Zettlemoyer ◽  
W. C. Walker
Keyword(s):  
Nitrogen Adsorption ◽  
X Ray ◽  
Surface Areas ◽  
Adsorption Surface

Carbon Black Surface Areas by the Harkins and Jura Absolute Method

1967 ◽  
Vol 40 (5) ◽  
pp. 1305-1310 ◽  
Author(s):  
G. Kraus ◽  
K. W. Rollmann
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Surface Area ◽  
Nitrogen Adsorption ◽  
Absolute Method ◽  
Carbon Blacks ◽  
Surface Areas ◽  
Particle Size Determination ◽  
Light Reflectance ◽  
Adsorption Surface

Abstract The Harkins and Jura (HJ) absolute method of surface area determination (Harkins and Jura, J. Am. Chem. Soc. 66, 919, 1944) has been applied to a large number of carbon blacks. Surface area is calculated from the heat of immersion of the solid powder covered by a preadsorbed multilayer of the immersion liquid. For non-porous carbon blacks good agreement with nitrogen adsorption surface areas is obtained, but with porous blacks the HJ method gives smaller values since micropores are filled and bridged over by the pre-adsorbed film. Thus the HJ areas are more nearly representative of particle size and may be used to calibrate indirect methods of particle size determination. An example of this is shown using light reflectance values on dry carbon black and possible complications due to particle size distribution in the use of the reflectance test are discussed.

Catalytic Olefin Hydroalkoxylation by Nano Particles of Pollucite

2015 ◽  
Vol 68 (6) ◽  
pp. 981 ◽  
Author(s):  
Sara Zamanian ◽  
Ali Nemati Kharat
Keyword(s):  
Nitrogen Adsorption ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nano Catalyst ◽  
Aromatic Alcohols ◽  
Electron Microscopy Analysis ◽  
Adsorption Surface ◽  
Microscopy Analysis ◽  
Temperature Programmed

The catalytic hydroalkoxylation of α,β-unsaturated esters, nitriles, and ethers with aliphatic and aromatic alcohols over pollucite using thermal and microwave-assisted methods was investigated. To study the effect of the alcohol structures on the mechanism of the hydroalkoxylation reaction, different alcohols, such as methanol to butanol, cyclohexanol, phenol, and 2-ethylhexanol were used. The activities of pollucite, in contrast to other basic solids, were scarcely affected by the presence of air and moisture. The correlation between alcohol acidity and reaction activity is discussed. The prepared pollucite was characterized by X‐ray diffraction, volumetric nitrogen adsorption surface area analysis, and CO2 temperature‐programmed desorption. Scanning electron microscopy analysis revealed that the size of the modified nano catalyst particles was under 40 nm.

scholarly journals Fabrication of activated carbon using two-step co-pyrolysis of used rubber and larch sawdust

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 8641-8652
Author(s):  
Jing Geng ◽  
Lu-Fei Li ◽  
Wen-Liang Wang ◽  
Jian-Min Chang ◽  
Chang-Lei Xia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Activated Carbon ◽  
Value Added ◽  
Physicochemical Characteristics ◽  
Activation Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Scanning Electron

Characteristics of the char produced in the co-pyrolysis of used rubber and larch sawdust were studied in the conversion of low-valued pyrolysis char into value-added activated carbon using two-step co-pyrolysis, namely pyrolysis and activation processes. The physicochemical characteristics of the chars were examined by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and scanning electron microscopy (SEM). The results revealed that after the two-step co-pyrolysis, the upgraded carbon had BET surface areas ranging from 600 m2 g−1 to 900 m2 g−1, which were higher than the requirements for activated carbon (American Water Works Association B600 standard). Additionally, as the sawdust/rubber ratio increased, the BET value increased accordingly. A possible reaction mechanism is proposed based on the experimental results during the activation process.

Study of the catalytic activity of Al-Fe pillared clays in the Baeyer–Villiger oxidation

Clay Minerals ◽  
2012 ◽  
Vol 47 (2) ◽  
pp. 275-284 ◽  
Author(s):  
L. S. Belaroui ◽  
A. Bengueddach
Keyword(s):  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Pillared Clays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dissolved Iron ◽  
Surface Areas ◽  
Accessible Surface ◽  
Adsorption Desorption ◽  
Villiger Oxidation

AbstractThree types of AlFePILCs pillared clays have been prepared from Algerian clay precursors. They have been characterized and tested in the Baeyer–Villiger oxidation of cyclohexanone to caprolactone using benzaldehyde and oxygen as oxidant at room temperature. The structural and textural properties of the catalyst have been determined by X-ray diffraction, nitrogen adsorption-desorption isotherms and Mössbauer spectroscopy.The different activities of the clays have been related to their Fe contents and accessible surface areas. The induction period observed before the reaction started has been attributed to the dissolution of a portion of the Fe3+ cations, mediated by either the perbenzoic acid intermediate or the benzoic acid co-product. The reaction was indeed catalysed by a few ppm of dissolved iron cations and the catalysis of the Baeyer–Villiger oxidation reaction should mechanistically be considered as homogeneous.

Investigation on Jurassic Shale Gas Reservoir Characteristics from Northern Qaidam Basin

2017 ◽  
Vol 748 ◽  
pp. 441-445
Author(s):  
Gui Xi Xu ◽  
Shu Zhong Wang ◽  
Xiang Rong Luo ◽  
Ze Feng Jing
Keyword(s):  
Mineral Content ◽  
Qaidam Basin ◽  
Nitrogen Adsorption ◽  
Test Results ◽  
X Ray Diffraction ◽  
Gas Reservoir ◽  
Average Pore ◽  
X Ray ◽  
Shale Gas Reservoir ◽  
Surface Areas

The Jurassic continental shale from northern Qaidam basin was selected as the research object, through the analysis of X-ray diffraction (XRD), field emission scanning electron microscopy (SEM) and nitrogen adsorption experiment, the mineral composition and pore structure characteristics of Jurassic continental shale from the northern Qaidam basin have been investigated in detail. All shale samples studied are quite rich in clay minerals. The clay mineral content ranges from 59.8% to 83.3% with an average of 74.6%, and the brittle mineral content accounts for 16.5% to 39.3%. Nitrogen adsorption test results indicate that for mesopores and macropores of shale samples the average pore width is 2~200 nm, mainly centering on 10~50 nm, and the micropores of the shale samples have a centralized distribution of 0.5~1 nm. The shale samples show high specific surface areas of 4.6~15.2 m2/g. According to SEM results, interparticle mineral matrix pores are main pore type and slit-type pore are well developed.

scholarly journals Structure, Texture and Catalytic Properties of Pd/SiO2 Catalysts

1996 ◽  
Vol 13 (5) ◽  
pp. 423-431 ◽  
Author(s):  
S.A. El-Hakam ◽  
Awad I. Ahmed ◽  
S.M. Hassan ◽  
H.M. Farage
Keyword(s):  
Active Site ◽  
Metal Content ◽  
Catalytic Properties ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
X Ray ◽  
Surface Areas ◽  
Dehydrogenation Of Cyclohexane ◽  
Adsorption Surface ◽  
Kinetics Of

The structural properties of Pd/silica catalysts have been investigated by means of DTA and X-ray techniques. The X-ray results indicate that Pd metal is the only phase formed. The textural properties were determined using low-temperature nitrogen adsorption. Surface areas were calculated and the dependence of the surface area on the metal content has been discussed. Pore structure analyses indicate the presence of both micro-and meso-pores. The dehydrogenation of cyclohexane was found to be affected by the metal content. The active site for the dehydrogenation process on Pd/silica catalysts consists of one Pd atom. The kinetics of the dehydrogenation exhibit a fractional order.

scholarly journals Some Environmentally Relevant Reactions of Cerium Oxide

2014 ◽  
Vol 13 (2) ◽  
pp. 148-161 ◽  
Author(s):  
Pavel Janoš ◽  
Jakub Ederer ◽  
Marek Došek
Keyword(s):  
Cerium Oxide ◽  
Flame Retardants ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cerium Oxides ◽  
Surface Areas ◽  
Bet Method ◽  
Phosphorus Containing ◽  
Scanning Electron

Abstract Reactive forms of cerium oxide were prepared by a thermal decomposition of various precursors, namely carbonates, oxalates and citrates, commercially available nanocrystalline cerium oxide (nanoceria) was involved in the study for comparison. Scanning electron microscopy (SEM) and x-ray diffraction analysis (XRD) were used to examine the morphology and crystallinity of the samples, respectively, whereas the Brunauer-Emmett-Teller (BET) method of nitrogen adsorption was used to determine surface areas. Interactions of cerium oxide with some phosphorus-containing compounds were investigated. Some of the examined samples, especially those prepared by annealing from carbonate precursors, exhibited an outstanding ability to destroy highly toxic organophosphates, such as pesticides (parathion methyl), or nerve agents (soman, VX). There were identified some relations between the degradation efficiency of cerium oxides and their crystallinity. It was also shown that cerium oxide is able to destroy one of widely used flame retardants - triphenyl phosphate. A phosphatase-mimetic activity of various cerium oxides was examined with the aid of a standardized phosphatase test.

scholarly journals Adsorption removing various basic nitrogen compounds from model diesel over allochroic silica gel

2018 ◽  
Vol 36 (9-10) ◽  
pp. 1595-1611
Author(s):  
Xin Hong ◽  
Yunhe Li ◽  
Chang Gao ◽  
Yonghua Zhao ◽  
Ke Tang
Keyword(s):  
Silica Gel ◽  
Nitrogen Adsorption ◽  
Nitrogen Compounds ◽  
X Ray Diffraction ◽  
Binding Model ◽  
Average Pore ◽  
X Ray ◽  
Surface Areas ◽  
Basic Nitrogen ◽  
Model Diesel

The adsorption removal of quinoline from model diesel by using alumina, diatomite, silica gel, and allochroic silica gel as adsorbents was investigated. The experiment results indicated that the adsorption denitrogenation performance of allochroic silica gel was more superior to other three adsorbents. The silica gel and allochroic silica gel were confirmed by characterization with X-ray diffraction, nitrogen adsorption–desorption, and ammonia temperature programmed desoption (NH3-TPD). X-ray diffraction results indicated that both the samples were amorphous structures. The average pore diameters of silica gel and allochroic silica gel were 18.46 and 1.80 nm, the Brunauer–Emmett–Teller surface areas were 437.86 and 623.39 m2/g, and the pore volumes were 0.9724 and 0.3442 cm3/g, respectively. The results of TPD showed that the acidity of allochroic silica gel was far stronger than that of silica gel which greatly enhanced its adsorption denitrogenation performance. The adsorption denitrogenation performance of allochroic silica gel for quinoline, aniline, and pyridine from model diesel was as follows: aniline, pyridine, and quinoline. Adsorption temperature, particle size, and arenes added in model diesel had little impact on the removal of aniline and pyridine except quinoline. The adsorbent-to-oil ratio had significant effects on adsorption denitrogenation, especially for quinoline. The N–Co bond between Co in allochroic silica gel and N atom in the basic nitrogen compounds molecule played a significant role. Furthermore, the allochroic silica gel could be easily regenerated by its adsorption denitrogenation performance for quinoline and pyridine by using calcination once or several times, except aniline. The adsorption isotherm results revealed that the adsorption of pyridine and aniline belonged to the Langmuir–Freundlich binding model, but the adsorption of quinoline belonged to Freundlich model.

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