scholarly journals Synthesis of activated carbon sand their application in the synthesis of monometallic and bimetallic supported catalysts

2020 ◽  
Vol 5 (4) ◽  
pp. 190-196
Author(s):  
DALILA BOUSBA ◽  
CHAFIA SOBHI ◽  
AMNA ZOUAOUI ◽  
SOUAD BOUASLA
Keyword(s):  
Heterogeneous Catalysis ◽  
Heterogeneous Catalysts ◽  
Bimetallic Catalyst ◽  
Activated Carbons ◽  
Supported Catalysts ◽  
Chemical Properties ◽  
Environmentally Benign ◽  
Organic Transformations ◽  
Long Time ◽  
Physical And Chemical

Biomass-derived porous carbons are attractive materials for the synthesis of carbon-supported catalysts, carbonaceous catalysts are environmentally benign and could provide an important competitive advantage as compared to existing heterogeneous catalysts, however the surface properties of carbon materials and excellent physical and chemical properties are compatible with diverse catalysis reactions including organic transformations. Currently, activated carbons are one of well known carbonaceous materials for their catalytic properties and for use as support in heterogeneous catalysis. The supported catalysts have been successfully used in the chemical industries for a long time, in which carbon supported catalysts have allowed to a new chemical catalytic process, on the other hand Heterogeneous catalysis plays a key role in the manufacture of essential products in different fields. In this paper, we present a comparative study, between two main different methods for activated carbons (ACs) preparation namely, physical and chemical activations. Latter was prepared from agro-industrial biomass and used as a support to prepare monometallic (dry impregnation and excess impregnation) and bimetallic catalyst (successive impregnation and co impregnation).

Carbon Nanocomposites: The Potential Heterogeneous Catalysts for Organic Transformations

2020 ◽  
Vol 24 ◽  
Author(s):  
Ambika ◽  
Pradeep Pratap Singh
Keyword(s):  
Heterogeneous Catalysis ◽  
Environmental Remediation ◽  
High Stability ◽  
Heterogeneous Catalysts ◽  
Low Cost ◽  
Chemical Properties ◽  
Organic Transformations ◽  
Wide Availability ◽  
Physical And Chemical ◽  
Carbon Based

: One of the major challenges in chemistry confronted by the chemists is the replacement of conventional homogeneous catalysts by heterogeneous catalysts for the development of green, sustainable and economical chemical processes. Recently, carbon based nanocomposites have attracted the attention of scientists due to their unique physical and chemical properties such as large surface area and pore volume, chemical inertness, high stability and high electrical conductivity. These NCs have been employed in energy storage, electronic devices, sensors, environmental remediation etc. Owing to the wide availability and low cost, carbon‐based‐materials have been utilized as supports for transition metals and other materials. The carbon based NCs offers a number of advantages such as high stability, easy recovery, reusability with often minimal leaching of metal ions, and green and sustainable approaches to heterogeneous catalysis for various organic transformations. Hence, they can be used as the substitute of the existing catalyst used for heterogeneous catalysis in industries. In this review, various processing methods for carbon based nanocomposites and their applications as heterogeneous catalyst for organic transformations like hydrogenation, oxidation, coupling, and multi‐component reactions, have been discussed.

scholarly journals g-C3N4/Ni Nanocomposite: An Efficient and Eco-Friendly Recyclable Catalyst for the Synthesis of Quinoxalines

Proceedings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 49 ◽  
Author(s):  
Rashidizadeh ◽  
Ghafuri
Keyword(s):  
Catalytic Activity ◽  
Heterogeneous Catalysts ◽  
Catalyst Support ◽  
Chemical Properties ◽  
Environmentally Benign ◽  
High Catalytic Activity ◽  
Active Chemical ◽  
Quinoxaline Derivatives ◽  
Physical And Chemical ◽  
And Chemical Properties

Presently, with increasing environmental concerns, the development of sustainable and friendly heterogeneous catalysts has attracted more and more attention, in both the scientific and industrial communities. Hence, the use of nanocatalysts with well-defined structures, that are environmentally benign, with high catalytic activity, and high chemical stability are desirable, instead of corrosive and hazardous chemicals. In recent years, polymeric mesoporous graphitic carbon nitride (g-C3N4) has turned out to be a fascinating choice for catalyst or catalyst support due to its special physical and chemical properties, thermal stability, non-toxicity, unique electronic properties, and large surface area. The incorporation of nitrogen atoms in the carbon architecture of the g-C3N4 gives rise to the active chemical sites exposed on the surface. On the other hand, depositing metal nanoparticles onto g-C3N4 is an effective strategy to enhance the catalytic activity of g-C3N4. In the present study, g-C3N4/Ni as a recyclable and highly efficient heterogeneous catalyst, with a good porous structure, has been prepared and its catalytic activity was investigated for the synthesis of quinoxaline derivatives.

Triclinic boron nanosheets high-efficient electrocatalysts for water splitting

2021 ◽  
Author(s):  
Maoping Xu ◽  
Rui Wang ◽  
Kan Bian ◽  
Chuang Hou ◽  
Yaxing Wu ◽  
...  
Keyword(s):  
Active Sites ◽  
Theoretical Calculations ◽  
Chemical Properties ◽  
Chemical Vapor ◽  
Energy Storage And Conversion ◽  
High Efficient ◽  
Long Time ◽  
Time Cycle ◽  
Metal Properties ◽  
Physical And Chemical

Abstract Recently, two-dimensional (2D) boron nanosheets have been predicted to exhibit exceptional physical and chemical properties, which is expected to be widely used in advanced electronics, optoelectronic, energy storage and conversion devices. However, the experimental application of 2D boron nanosheets in hydrogen evolution reactiuon (HER) has not been reported. Here, we have grown ultrathin boron nanosheets on tungsten foils via chemical vapor deposition (CVD). The prepared triclinic boron nanosheets are highly crystalline, which perfectly match the structure in the previous theoretical calculations. Notably, the boron nanosheets show excellent HER performance. The Tafel slope is only 64 mV/dec-1 and the nanosheets can maintain good stability under long-time cycle in acidic solution. The improvement of performance is mainly due to the metal properties and a large number of exposed active sites on the boron nanosheets, which is confirmed by first-principle calculations.

Enhancement of Cu(II) adsorption on activated carbons by non-thermal plasma modification in O2, N2 and O2/N2 atmospheres

2020 ◽  
Vol 18 (4) ◽  
Author(s):  
Long Wu ◽  
Yimeng Cai ◽  
Jiayong Tu ◽  
Shizhe Wang ◽  
Noriyuki Kobayashi ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Thermal Plasma ◽  
Activated Carbons ◽  
Chemical Properties ◽  
Plasma Modification ◽  
Adsorption Performance ◽  
Ft Ir ◽  
Non Thermal Plasma ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractActivated carbon (AC) was modified by using non-thermal plasma in O2, N2 and O2/N2 atmospheres to increase its Cu(II) adsorption capacity and quantify the influences of the modifying atmospheres. SEM, BET, FT-IR and XPS were used to characterize the surface physical and chemical properties of AC. The results show that the AC modified by using plasma had significantly better Cu(II) adsorption performance than the raw AC. Among the O2, N2 and O2/N2 atmospheres, the AC with plasma modification in N2 showed best Cu(II) adsorption performance and the Cu(II) adsorption capacity was 369.5% higher than the raw AC. The AC modified in O2 atmosphere can form C—COOH groups, while the AC modified in N2 atmosphere can form C—NH2 groups. These two groups are both beneficial for Cu(II) adsorption, where the —NH2 groups are more effective for Cu(II) adsorption compared to —COOH groups. The chemisorption dominated the Cu(II) adsorption on the plasma modified AC and the adsorption performance was dependent on the surface functional groups properties of AC.

Using New Porous Nanocomposites for Photocatalytic Water Decontamination

2008 ◽  
Vol 1145 ◽  
Author(s):  
Maryam Zarei Chaleshtori ◽  
S. M. Sarif Masud ◽  
Geoffrey B. Saupe
Keyword(s):  
Organic Contaminants ◽  
Heterogeneous Catalysts ◽  
Organic Pollutant ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Polluted Water ◽  
Particle Sizes ◽  
Water Decontamination ◽  
Physical And Chemical

AbstractHeterogeneous catalysts that accelerate the photolytic destruction of organic contaminants in water are a potentially inexpensive and highly effective way to remove both trace-level and saturated harmful compounds from industrial waste streams and drinking water. Porous photocatalytic materials can have the combined qualities of high surface area and relatively large particle sizes, as compared with nanoparticulate catalyst powders like titanium dioxide . The larger particle sizes of the porous materials facilitate catalyst removal from a solution, after purification has taken place.We have synthesized new kinds of photocatalytic porous oxide materials that can be used to purify contaminated water by accelerating the photodegradation of any kind of organic pollutant. The new materials have very large open pore structures that facilitate the diffusion, the surface contact of contaminants, and solvent flow through the catalyst. These qualities enhance surface reactions important to the process. The new catalysts have shown robust physical and chemical properties that make them candidates for real applications in polluted water decontamination.

scholarly journals Radiation resistance of borosilicate glass to beta and gamma radiation evaluated using the accelerated proton method

2021 ◽  
Vol 14 (1) ◽  
pp. 8-18
Author(s):  
A. S. Aloy ◽  
◽  
N. V. Kovalev ◽  
A. M. Prokoshin ◽  
N. F. Karpovich ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Borosilicate Glass ◽  
Chemical Properties ◽  
High Level Waste ◽  
Time Period ◽  
Long Time ◽  
Radiation Induced ◽  
Intermediate Storage ◽  
High Level ◽  
Physical And Chemical

Preservation of the main physical and chemical properties of vitrified high-level waste over a long-time period under the influence of heavy radiation exposure is considered as an essential criterion for its quality assessment used to demonstrate the safety of intermediate storage under controlled conditions and subsequent final disposal of the waste. Earlier calculations covering a time period of up to 104 years allowed to identify the maximum beta- and gamma-radiation induced dose loads for borosilicate glass (BSS) of a basic composition specifically designed to vitrify liquid HLW from ODC MCC [1]. This study evaluates potential feasibility of applying an accelerated proton beam to simulate radiation damage according to the type of beta-gamma effects produced on the BSS and investigates the consequences of such effects on its properties which is seen as a distinctive feature of this research.

scholarly journals Anthracite-based activated carbons for the efficient solution of important environmental problems

2021 ◽  
Vol 6 (1) ◽  
pp. 30-41
Author(s):  
Victor M. Mukhin
Keyword(s):  
Activated Carbons ◽  
Chemical Properties ◽  
Environmental Safety ◽  
Raw Material ◽  
New Production ◽  
Safety Issues ◽  
Carbon Adsorption ◽  
Wide Range ◽  
Activated Coal ◽  
Physical And Chemical

This article examines the issues of environmental pollution as a result of man-made activities and determines the most effective ways to protect the biosphere with the help of carbon-adsorption technologies. Due to their physical and chemical properties, activated carbons are an ideal adsorbent and allow solving a wide range of environmental safety issues. Based on the theoretical assumptions expressed by Academician M. M. Dubinin, it is shown that anthracite is an excellent raw material for producing activated coal. A technology for obtaining СAS (Crushed Anthracite Sorbent) grade activated carbons from anthracite has been developed and its adsorption properties have been studied. Tests of СAS activated carbon in the purification of drinking water and wastewater, protection of the atmosphere from harmful gases and vapors, and detoxification of soils from herbicide residues were carried out. The necessity and requirements for the creation of new production facilities for active coals based on anthracite in Russian coal basins are substantiated.

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