Analysis of Activation Process of Carbon Black Based on Structural Parameters Obtained by XRD Analysis

Lee, Sang‐Min; Lee, Sang-Hye; Roh, Jae-Seung

doi:10.3390/cryst11020153

Cited by 119 publications

(50 citation statements)

References 44 publications

(51 reference statements)

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“…It should be noted that the peak corresponding to the graphite structure has a diffuse left shoulder. This peak shape is associated with the presence of LGC [ 40 ] or turbostratic graphite, [ 41 ] in which the interplanar distance d002 is larger than for highly graphitizable carbon (HGC). It was found in ref [40].…”

Section: Resultsmentioning

confidence: 99%

Electric Arc Synthesis of Composite Ni–C, NiO–C Nanomaterials: Structure and Electrochemical Properties

Зайковский

Ukhina

Mateishina

2022

Physica Status Solidi (a)

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Plasma-chemical synthesis of nanomaterials is becoming more and more developed every year. One approach to plasma-chemical synthesis is the use of an electric arc discharge. The high temperatures of the discharge plasma lead to the dispersion of the consumed electrodes and the formation of a gaseous plasma-chemical system. Further expansion of the components of this mixture in the reactor chamber leads to the processes of mixing with a buffer gas, cooling, condensation, and formation of the structure of nanomaterials. In this case, the structure and composition of the formed nanomaterials strongly depend on both the composition of the plasma-chemical system and the cooling rate during expansion. [1] The most common use of carbon as a sputtered material leads to the formation of such carbon nanostructures as fullerenes, [2] graphene flakes. [3] It is known that the addition of elements such as Sn, [4] Pt, [5] Pd [6] to carbon in a plasmachemical system leads to the formation of spherical metal nanoparticles packed in a carbon matrix. The addition of such elements as W, [7] Al, [8] Fe [9] to the plasma-chemical system leads to the formation of carbide nanoparticles in the carbon matrix. In addition, the presence of certain elements affects the formation of the carbon structure itself. Thus, the presence of hydrogen, [10] oxygen, [11] or silicon [12,13] in a plasma-chemical system leads to the formation of the structure of graphene flakes. The presence of nanoparticles of the iron family (Fe, [14] Co, [15] Ni [16] ) stimulates the formation of carbon nanotubes.The processes occurring during the interaction of metal and carbon depend on such factors as the affinity of the metal to carbon, the crystal structure of metals, the ability and enthalpy of formation of carbides, the solubility of carbon in the crystal lattice, etc. The most widely studied interaction is the heating of carbon with nickel, cobalt and iron, which are well saturated with carbon and lead to graphitization of the carbon structure, while the interaction with metals such as copper or titanium does not lead to graphitization. [17] Another important factor is the size of the metal particles. Due to the large ratio of surface to bulk atoms, the melting temperature in nanoscale structures decreases and the solubility of carbon increases. [18][19][20] In this case, the graphitization of amorphous carbon in the presence of nickel nanoparticles occurs at a much lower temperature (250-300 °C) compared to bulk particles (600 °C). [21] The interaction of metal nanoparticles with carbon has been extensively studied in the field of carbon nanotube (CNT) synthesis. The mechanisms of CNT formation in the course of plasma-chemical synthesis include the formation of a carbon-saturated metal particle in the gas atmosphere, which, upon cooling, releases carbon on the surface in the form of CNTs. [22] This mechanism in a more developed form was called vapor-liquid-solid (VLS), and describes in more detail that the metal catalyst in the solid state poorly adsorbs molec...

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Section: Resultsmentioning

confidence: 99%

Electric Arc Synthesis of Composite Ni–C, NiO–C Nanomaterials: Structure and Electrochemical Properties

Зайковский

Ukhina

Mateishina

2022

Physica Status Solidi (a)

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“…The number of active sites is strongly dependent upon porosity or surface area as they are associated with edges or defects on the surface [30,31]. The higher reactivity of chars obtained during pyrolysis in CO 2 atmosphere can by caused by the inclusion of oxygen and elevated total surface area, leading to the formation of new pores or the closing of pores opened by CO 2 [32,33]. Hence, the atmosphere in which the pyrolysis of tire waste was carried out affected the above-mentioned properties and, consequently, the reactivity of the received tire char.…”

Section: Analysis Of Tga Resultsmentioning

confidence: 99%

“…Hence, the atmosphere in which the pyrolysis of tire waste was carried out affected the above-mentioned properties and, consequently, the reactivity of the received tire char. It can be concluded that, at the stage of pyrolysis in an atmosphere of carbon dioxide, there is an initial activation of the char consisting of the development of a porous structure [33], which translates into its greater reactivity. In the work [15], it was found that the differences of pore volumes of chars obtained under N 2 and CO 2 flows were most likely caused by a difference in the diffusivity of volatiles in the two different atmospheres.…”

Section: Analysis Of Tga Resultsmentioning

confidence: 99%

Effect of Pyrolysis Atmosphere on the Gasification of Waste Tire Char

2021

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The aim of the study is to assess the influence of the atmosphere during pyrolysis on the course of CO2 gasification of a tire waste char. Two approaches were used: the pyrolysis step was carried out in an inert atmosphere of argon (I) or in an atmosphere of carbon dioxide (II). The examinations were carried out in non-isothermal conditions using a Rubotherm DynTherm thermobalance in the temperature range of 20–1100 °C and three heating rates: 5, 10 and 15 K/min. Based on the results of the gasification examinations, the TG (Thermogravimetry) and DTG (Derivative Thermogravimetry) curves were developed and the kinetic parameters were calculated using the KAS (Kissinger-Akahira-Sunose) and FWO (Flynn-Wall-Ozawa) methods. Additionally, the CO2 gasification of tire chars reaction order (n), was evaluated, and the kinetic parameters were calculated with the use of Coats and Redfern method. Tire waste char obtained in an argon atmosphere was characterized by lower reactivity, which was reflected in shift of conversion and DTG curves to higher temperatures and higher mean values of activation energy. A variability of activation energy values with the progress of the reaction was observed. For char obtained in an argon atmosphere, the activation energy varied in the range of 191.1–277.2 kJ/mol and, for a char obtained in an atmosphere of CO2, in the range of 148.0–284.8 kJ/mol. The highest activation energy values were observed at the beginning of the gasification process and the lowest for the conversion degree 0.5–0.7.

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“…Based on EDS signal and mapping results, the peaks at 9.59°, 15.12°, 19.20°, 28.97°, and 49.24° could be related to a phase or various phases of carbon (graphite, graphite oxide, graphite with Ru intercalated, or a mixture of these phases) [ 14 , 19 , 20 , 21 , 22 , 23 , 24 ]. Nevertheless, without further information, it is not possible to confirm that.…”

Section: Resultsmentioning

confidence: 99%

Hydrogen Oxidation and Oxygen Reduction Reactions on an OsRu-Based Electrocatalyst Synthesized by Microwave Irradiation

et al. 2021

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This work presents an OsRu-based electrocatalyst synthesis, by a rapid and efficient method through microwave irradiation. The outstanding electrocatalyst shows a dual catalytic activity, demonstrating both hydrogen oxidation and oxygen reduction reactions. The material is structural and morphologically characterized by FT-IR, X-ray diffraction, EDS, and SEM, indicating nanoparticulated Os and Ru metallic phases with a crystallite size of ∼6 nm, calculated by the Scherrer equation. The metal nanoparticles are apparently deposited on a carbonaceous sponge-like morphology structure. Its electrochemical characterization is performed in 0.5 M H2SO4 by the rotating disk electrode technique, employing cyclic and linear sweep voltammetry. Two different ink treatments have been studied to improve the obtained polarization curves. The material was also tested in the presence of methanol for the oxygen reduction reaction, showing an important resistance to this contaminant, making it viable for its use in direct methanol fuel cells (DMFCs) as a cathode and in polymer electrolyte fuel cells (PEMFCs) as an anode as much as a cathode.

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Analysis of Activation Process of Carbon Black Based on Structural Parameters Obtained by XRD Analysis

Cited by 119 publications

References 44 publications

Electric Arc Synthesis of Composite Ni–C, NiO–C Nanomaterials: Structure and Electrochemical Properties

Electric Arc Synthesis of Composite Ni–C, NiO–C Nanomaterials: Structure and Electrochemical Properties

Effect of Pyrolysis Atmosphere on the Gasification of Waste Tire Char

Hydrogen Oxidation and Oxygen Reduction Reactions on an OsRu-Based Electrocatalyst Synthesized by Microwave Irradiation

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