Reduction Of Copper And Iron Oxide Mixture With Local Reducing Gases,
2020
Tashkent State Technical University named after Islam Karimov
Reduction Of Copper And Iron Oxide Mixture With Local Reducing Gases, Shokhrukh Khojiev
Acta of Turin Polytechnic University in Tashkent
The article analyzes the scientific problems of the copper industry. In particular, the main problem with the classical production of copper is the causes of large amounts of slag and the negative impact of these wastes on the environment. Accordingly, the main component that forms the slag is iron, and the higher its content in the original copper concentrate, the more slag is formed, and at the same time a large amount of copper metal is released into the waste. The departure is indicated by evidence. To prevent this problem, a technology has been proposed to reduce copper sulfide concentrates …
Understanding The Role Of Atom Trapping In The Evolution Of Hydrocarbon Transformation Catalyst Morphology,
2020
University of New Mexico
Understanding The Role Of Atom Trapping In The Evolution Of Hydrocarbon Transformation Catalyst Morphology, Griffin Alexander Canning
Chemistry and Chemical Biology ETDs
Converting alkanes to other, more chemically and economically valuable molecules requires catalysts that can survive elevated temperatures and highly reducing environments. These environments can cause many metal-nanoparticle based catalysts to sinter rapidly, causing a loss of activity. They must also tolerate the coke formation, as well, since coke can restrict access to active sites by gas phase molecules, thus lowering catalytic activity. While there are routes to improve both the sinter and coke resistance of catalysts, an alternative strategy is to develop a protocol for regenerating the activity of the catalyst in question when coke formation or sintering becomes problematic. …
Atom Trapping And Its Role On The Nucleation & Growth Of Platinum Nanoparticles,
2020
University of New Mexico
Atom Trapping And Its Role On The Nucleation & Growth Of Platinum Nanoparticles, Deepak Kunwar
Chemistry and Chemical Biology ETDs
Diesel oxidation catalysts deactivate due to Pt sintering, a major problem in automotive industries. To make sure they operate effectively throughout the lifetime of the vehicle, automotive industries are putting an excessive amount of Pt. There is a need to develop a catalyst that serves long term performance with minimal use of Pt. Jones et al.1 demonstrated that ceria traps Pt atoms. His work generated some logical and valid questions such as what is the mechanism for the formation of anomalously large Pt particles? What is the upper limit of Pt metal loading in the form of single atoms …
Facile Synthesis Of Nitrogen-Doped Graphene-Like Active Carbon Materials For High Performance Lithium-Sulfur Battery,
2020
1. Institute for Clean Energy & Advanced Materials, School of Materials and Energy, Southwest University, Chongqing 400715, P.R. China;
Facile Synthesis Of Nitrogen-Doped Graphene-Like Active Carbon Materials For High Performance Lithium-Sulfur Battery, Quan-Hua Meng, Wen-Wen Deng, Chang-Ming Li
Journal of Electrochemistry
Lithium-sulphur (Li-S) battery is regarded as a promising energy storage device because of its high theoretical capacity. However, the low S utilization and short cycling life limit the commercial applications. In this work, nitrogen-doped graphene-like carbon (NGC) materials were synthesized by simply pyrolyzing and carbonizing the mixture of melamine (C3H6N6) and L-cysteine (C3H7NO2S). The graphene-like structure in NGC effectively buffered the volume change of S during the discharge/charge process and improved the cycling stability. Meanwhile, nitrogen-containing functional groups in NGC facilitated the transportation of ions and suppressed the …
A Model For The Anodic Carbonization Of Alkaline Polymer Electrolyte Fuel Cells,
2020
College of Chemistry and Molecular Sciences, Hubei Key Lab of Electrochemical Power Sources, Wuhan University, Wuhan 430072, China;
A Model For The Anodic Carbonization Of Alkaline Polymer Electrolyte Fuel Cells, Qi-Hao Li, Ying-Ming Wang, Hua-Long Ma, Li Xiao, Gong-Wei Wang, Jun-Tao Lu, Lin Zhuang
Journal of Electrochemistry
The alkaline polymer electrolyte fuel cell (APEFC) has made appreciable progress in recent years but is still suffering performance loss during discharge with air as the oxidant. Several theories have been suggested to interpret the loss. However, efforts are still needed to reach a clear quantitative understanding. Based on the major experimental findings in combination with thermodynamics and kinetics of the reactions involved in the anode, this paper presents a model featuring layered carbonization in the anode and relevant grouped equations. The simulation results generated from the latter are compared with experiments, and possible principles to suppress the performance loss …
Mucilage-Capped Silver Nanoparticles For Glucose Electrochemical Sensing And Fuel Cell Applications,
2020
Menoufia Company for Water and Wastewater, Holding Company for Water and Wastewater, Menoufia
Mucilage-Capped Silver Nanoparticles For Glucose Electrochemical Sensing And Fuel Cell Applications, Ziad Khalifa, Moustafa Zahran Dr, Magdy Zahran Prof, Magdi Abdel Azzem Prof
Chemical Engineering
A simple, cost-effective and green mucilage-capped silver nanoparticles (Mucilage-AgNPs) modified glassy carbon electrode (GC) composite was constructed for efficient and facile electrochemical oxidation of glucose for the first time. Mucilage-AgNPs were synthesized through the direct chemical reduction of Ag+ by mucilage extracted from Opuntia ficus-indica. Mucilage-AgNPs were identified and characterized using ultraviolet-visible spectroscopy, transmission electron microscopy and square wave voltammetry. Modification of the GC with AgNPs was carried out via a transfer-sticking technique with an immobilization time of 1 h. The Mucilage-AgNPs/GC composite was studied as a possible anode for glucose oxidation in a biofuel cell. The composite resulted in …
Modification Of Inuline By Iodic Acid,
2020
Tashkent Chemical-Technological Institute
Modification Of Inuline By Iodic Acid, Rakhmanberdiyev Gappar, Ibragimova Кomila, Аxmedov Оliy
CHEMISTRY AND CHEMICAL ENGINEERING
In order to further modify inulin with drugs, the process of introducing reactive aldehyde groups into the inulin macromolecule was carried out. Aldehyde groups were introduced by oxidizing inulin with iodic acid. The process of oxidation of inulin and cellulose with iodic acid was compared. The quantities of aldehyde groups in the oxidized samples were estimated, their molecular weights were determined, IR spectra were measured, the iodine number of the inulin dialdehyde and their oxidation state were determined.
Synthesis Of 1,2,3-Triazoles Based On Propargyl Ethers Of Carbamate,
2020
Tashkent state dental institute
Synthesis Of 1,2,3-Triazoles Based On Propargyl Ethers Of Carbamate, Djuraev Abdukahhor, Yakubxodjaeva Malika, Ataxodjaeva Matluba, Gaibullaev Oibek
CHEMISTRY AND CHEMICAL ENGINEERING
By the interaction of propargyl esters of carbamate derivatives with phenylazide, 1,2,3- triazole derivatives were synthesized. Their anti-inflammatory activity was subsequently studied.During the study of biological activity, a relationship was established between the anti- inflammatory activity and the chemical structure in the studied series of 1,2,3-triazole derivatives.
The Research Of Conditions For The Formation Of Phenol Formaldehyde Resins Modified With Hydroxyl Containg Polyether Polyol,
2020
Tashkent Chemical-Technological Institute
The Research Of Conditions For The Formation Of Phenol Formaldehyde Resins Modified With Hydroxyl Containg Polyether Polyol, Magrupov Farkhad, Umarov Sherali, Tohirov Murodjon, Radjabova Zukhra
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of the study was to study the conditions of copolycondensation of phenol alcohol with hydroxyl-containing polyether polyol in the presence of maleic anhydride chain extender in order to obtain modified thermoset phenolic-formaldehyde oligomers. Investigation of the dependence of the content of free phenol, formaldehyde and methylol groups on time during the synthesis of the modified phenol-formaldehyde resin with the ratios hydroxyl-containing polyether polyol:phenol alcohol 1:60 mol/mol and 1:100 mol/mol. It was revealed that maleic anhydride, present in the reaction medium as a copolycondensation catalyst, also participates in copolycondensation reactions as a chain extender. Moreover, as the molar fraction …
Vinylation By 3,6-Dimetyloctin-4-Diol-3,6 Acetylene,
2020
Tashkent chemical-technological Institute
Vinylation By 3,6-Dimetyloctin-4-Diol-3,6 Acetylene, Yusupova Lola, Abdukarimova Saida, Rajabov Rustambek, Khalimova Oygul
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of the research work elaboration of technology of obtaine of acetylene diols and their vinyl ethers. Reaction of formation mono di vinyl ethers as a result vinyl 3,6-dimetyloktin-4-diol-3,6 by acetylene, and also influence of solvents, the catalyst and its quantity, duration of reaction, temperatures is investigated. Are defined speed of reaction. Recommended vinyl 3,6-dimetyloktin-4-diol-3,6 acetylene in the presence of highly basic systems at atmospheric pressure.
Synthesis And Research Of New Heterometal Complexes Cо(Ii), Ni(Ii), Cu(Ii) And Mn(Ii) Based On V(V) And 5-(4-Pyridyl)-1,3,4-Oxadiazole-2(3h)-Thione Lubricants,
2020
National University of Uzbekistan, Tashkent
Synthesis And Research Of New Heterometal Complexes Cо(Ii), Ni(Ii), Cu(Ii) And Mn(Ii) Based On V(V) And 5-(4-Pyridyl)-1,3,4-Oxadiazole-2(3h)-Thione Lubricants, Pirimova Mehribon, Kadirova Shakhnoza, Rakhmonоva Dilnoza, Ziyayev Abduhakim
CHEMISTRY AND CHEMICAL ENGINEERING
The oxadiazole derivatives complex compounds with metals are biologically active substances. The aim of the study was to study the interaction of the chlorides of Co (II), Ni (II), Cu (II) and Mn (II) with 5-(4-pyridyl)-1,3,4-oxadiazole-2(3H)–thione, ammonium vanadate. Competitive coordination of donor centers, electronic and geometric structures of the ligand molecule were studied on the basis of the quantum-chemical software package Gaussian09 LanL2DZ. It was shown that 5-(4-pyridyl)-1,3,4-oxadiazole-2(3H)-thione ligand is partially coordinated through a localized nitrogen or sulfur atoms at formation of the complex. А procedure was developed for the synthesis of new mixed-metal complexes. The composition and structure of …
Research Of Kinetic Characteristics Of The Process Of Decomposition Of Zinc Concentrate With Hydrochloric Acid,
2020
Tashkent Chemical Technological Institute
Research Of Kinetic Characteristics Of The Process Of Decomposition Of Zinc Concentrate With Hydrochloric Acid, Rosilov Mansur, Deng Tianlong, Usmanov Ilham, Samadiy Murodjon
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of the study was the theoretical justification of the kinetic characteristics of the process of producing zinc chloride from zinc concentrate of the Khandiza deposit. For this, the effect of temperature and duration of the process of autoclave zinc extraction in a 28% hydrochloric acid solution was studied at a ratio of Zn: HCI = 1:1.1. Variable parameters were the temperature of 70, 80 and 90 °C and the duration of the leaching process of 6, 8 and 10 hours. The optimal parameters for the production of zinc chloride were determined.
The Study Of The Component Composition Of The Reaction Mixture Containing Formaldehyde Reaction Products,
2020
Tashkent Chemical-Technological Institute
The Study Of The Component Composition Of The Reaction Mixture Containing Formaldehyde Reaction Products, Hurramov Lochinbek, Alimukhamedova Nozima, Adilov Ravshan, Alimukhamedov Muzafar
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of this work is to study the effect of the conditions of the reaction of monoethanolamine (Meol) with formaldehyde (FD) on the composition of the reaction mixture. Interaction of monoethanolamine with formaldehyde leads to the formation of N,N’,N”-tris(β-oxyethyl) hexahydro-S-triazine or N,N-bisoxazolidine. The type of final product was determined by the conditions of the reaction and the molar ratio of aminoalcohol:formaldehyde. The chromatogram of the vacuum-distilled final product obtained at the molar ratio of monoethanolamine:formaldehyde=1:1 shows on an individual compound with a retention time of 4.173 s. With increase in the molar ratio of monoethanolamine:formaldehyde=1: 2, the final product …
Isotherm And Kinetics Study For The Adsorption Of Nitrate From An Aqueous Solution Using A Modified Rice Straw,
2020
The British University in Egypt
Isotherm And Kinetics Study For The Adsorption Of Nitrate From An Aqueous Solution Using A Modified Rice Straw, Dalia A. Ali Eng, Mohamed A. Sadek Prof., Nagwa Mahmoud Al-Mansi Prof, Ahmad Wafiq Aboelnasr Dr.
Chemical Engineering
In this research, modified rice straw (MRS) is proposed. The proposed production process of the modified rice straw (MRS) adsorbent is carried out by precipitation of iron nano particles on the surface of acid activated rice straw. The nitrate adsorption is carried out through batch experiments. The optimum nitrate removal 94.8 % was achieved at pH = 7, adsorbent dose 3 = g/L, 150 rpm, initial nitrate concentration = 23 mg/L and contact time 180 = min. The new adsorbent synthesis, kinetics and isotherm models were studied. The nitrate adsorption was well described by pseudo second order kinetic model (R2 …
Recent Progress In Bifunctional Catalysts For Zinc-Air Batteries,
2020
1. State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Environmental Science and Engineering, Donghua University, Shanghai 201620, China;2. University of Louisiana at Lafayette, Lafayette, LA 70504, USA;
Recent Progress In Bifunctional Catalysts For Zinc-Air Batteries, Neng-Neng Xu, Jin-Li Qiao
Journal of Electrochemistry
Zinc-air battery has attracted great attention from researchers due to its high energy density and power density, which is expected to be widely used in energy conversion and storage. Air electrode as the core area of oxygen catalytic reaction is the focus of the entire zinc-air battery research. Recently, many research achievements have been made in non-noble metal bifunctional catalysts/electrodes with high activity, low cost and abundant species. In this review, we mainly focus on the reaction mechanism and the recent progress in non-noble metal oxide catalyst, carbon-based catalyst, and carbon-based transition metal compound composite and self-supporting electrode. In addition, …
Research Progress Of Metal-Nitrogen-Carbon Catalysts Toward Oxygen Reduction Reaction Inm Changchun Institute Of Applied Chemistry,
2020
1. State Key Laboratory of Electroanalytica Chemistry, Changchun Institute of Applied Chemistry,Chinese Academy of Sciences University of Chinese Academy of Sciences, Changchun 130022,Jilin, China;2. University of Science and Technology of China, School of Applied Chemistry & Engineering, Hefei 230026, Anhui, China;
Research Progress Of Metal-Nitrogen-Carbon Catalysts Toward Oxygen Reduction Reaction Inm Changchun Institute Of Applied Chemistry, Ming-Jun Xu, Jie Liu, Jun-Jie Ge, Chang-Peng Liu, Wei Xing
Journal of Electrochemistry
The development of highly active and stable catalysts toward oxygen reduction reaction (ORR) has been facing severe challenges. In recent years, pyrolytic M-N-C catalysts and metal-organic framework derived materials made the performance of non-noble metal catalysts greatly improved, however, the molecular and atomic level understanding in the reaction active sites and the mechanism are still lacking. Here, we summarize the recent research progress made in the Changchun Institute of Applied Chemistry. We present a microporous metal-organic-framework confined strategy toward the preferable formation of ORR catalysts. Firstly, we studied the active site and proposed a new active site structure for the …
Electrochemical Carbon Dioxide Reduction In Flow Cells,
2020
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, Jiangsu, China;
Electrochemical Carbon Dioxide Reduction In Flow Cells, Jia Fan, Na Han, Yan-Guang Li
Journal of Electrochemistry
Electrochemical carbon dioxide reduction (CO2RR) is an appealing approach to convert atmospheric CO2 to value-added fuels and industrial chemicals, and may play an important role during the transition to a carbon-neutral economy. In order to make this technology commercially viable, it is essential to pursue CO2RR in flow reactors instead of conventional H-type reactors, and to combine electrocatalyst development with system engineering. In this review, we overview the cell configurations and performance advantages of the two types of flow reactors, analyze their shortcomings, and discuss the effects of their different components including gas diffusion electrode …
Electrolyte Tailoring For Electrocatalytic Reduction Of Stable Molecules,
2020
Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Renewable Energy Conversion and Storage Center (ReCast), College of Chemistry, Nankai University, Tianjin 300071, China;
Electrolyte Tailoring For Electrocatalytic Reduction Of Stable Molecules, Jin-Han Li, Fang-Yi Cheng
Journal of Electrochemistry
Reduction of stable molecules such as CO2 and N2 is important process in electrochemical energy conversion and storage technologies for electrofuels production. However, for the inert nature of CO2/N2 molecule and competitive proton reduction in conventional aqueous electrolytes, selective electrochemical carbon/nitrogen fixation suffers from high overpotential, low reaction rate and low selectivity. While addressing these issues has witnessed substantial advances in electrocatalysts, much less attention has been placed on the electrolytes, which play an important role in regulating the local environment and thus the performance of catalysts under operating conditions. Rational design of electrolytes has …
Fuel Cell Performance Of Non-Precious Metal Based Electrocatalysts,
2020
1. Jiangsu Aoxin NEV Co., Ltd, Yancheng, Jiangsu, 224000, China;2. Department of Chemical and Biological Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China;3. Shanghai AI NEV Innovative Platform Co., Ltd, Shanghai, 201805, China;4. Yangtse Delta Academy of NEV CO.,LTD, Yancheng, Jiangsu, 224000, China;
Fuel Cell Performance Of Non-Precious Metal Based Electrocatalysts, Yan-Feng Zhang, Fei Xiao, Guang-Yu Chen, Min-Hua Shao
Journal of Electrochemistry
The commercialization of proton exchange membrane fuel cells (PEMFCs) is hindered by high cost and low durability of Pt based electrocatalysts. Developing efficient and durable non-precious metal catalysts is a promising approach to addressing these conundrums. Among them, transition metals dispersed in a nitrogen (N)-doped carbon support (M-N-C) show good oxygen reduction reaction activity. This article reviews recent progress in M-N-C catalysts development, focusing on the catalysts design, membrane electrode assembly fabrication, fuel cell performance, and durability testing. Template-assisted approach is an efficient way to synthesize M-N-C materials with homogeneously dispersed single atom active site and reduced metal particles, carbides …
Recent Progress On Enhancing Effect Of Nanosized Metals For Electrochemical Co2 Reduction,
2020
State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
Recent Progress On Enhancing Effect Of Nanosized Metals For Electrochemical Co2 Reduction, Yu-Ning Zhang, Dong-Fang Niu, Shuo-Zhen Hu, Xin-Sheng Zhang
Journal of Electrochemistry
The electrochemical conversion of CO2 to chemical raw material for further utilization shows promising future to alleviate global warming and realize carbon cycle in nature, which is of great significance to the green chemistry and sustainable development. This review briefly introduces the advantages of CO2 electrochemical reduction (CO2ER) and its basic reaction principles, and summarizes the recent progress in a series of activity enhancement strategies based on nanosized metal catalysts. The influences of alloy effect, interface engineering, synergistic effect, surface defect engineering and support effect on the catalytic performance of nanosized metals for CO2ER …
