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4,518 full-text articles. Page 78 of 140.

Electroactivities Of Pd/Fe3O4-C Catalysts For Electro-Oxidation Of Methanol, Ethanol And Propanol, Tao ZOU, Qing-feng YI, Yuan-yuan ZHANG, Xiao-ping LIU, Guo-rong XU, Hui-dong NIE, Xiu-lin ZHOU 2017 School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;

Electroactivities Of Pd/Fe3O4-C Catalysts For Electro-Oxidation Of Methanol, Ethanol And Propanol, Tao Zou, Qing-Feng Yi, Yuan-Yuan Zhang, Xiao-Ping Liu, Guo-Rong Xu, Hui-Dong Nie, Xiu-Lin Zhou

Journal of Electrochemistry

Development of palladium (Pd) catalysts with high electroactivity for alcohol oxidation is significant for alcohol fuel cells. In this work, Pd nanoparticles were formed by sodium borohydride (NaBH4) reduction method and subsequently deposited on the surface of carbon supported ferriferrous oxide (Fe3O4/C) composites to obtain the Pd/Fe3O4-C catalysts with different Fe3O4 loadings. Their transmission electron microscopic (TEM) images show that the Pd nanoparticles were uniformly dispersed on the Fe3O4/C. Electroactivities of the prepared Pd/Fe3O4-C catalysts toward oxidations of C1-C3 …


Cobalt-Based Nitrogen-Doped Carbon Non-Noble Metal Catalysts For Oxygen Reduction Reaction, Meng-xiu JIANG, Jing ZHANG, Yue-hua LI, Rong ZHANG 2017 College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China;

Cobalt-Based Nitrogen-Doped Carbon Non-Noble Metal Catalysts For Oxygen Reduction Reaction, Meng-Xiu Jiang, Jing Zhang, Yue-Hua Li, Rong Zhang

Journal of Electrochemistry

Transition metal-nitrogen co-doped carbon catalysts have attracted significant attention because of their reasonable activity and remarkable selectivity toward oxygen reduction reaction (ORR) as cathodic reaction in fuel cells. However, the role of transition metal in the active sites of the catalysts still is uncertain. In this work, the Cox-Ny/C-T catalysts were prepared with BP2000 as a carbon source, urea (Ur) as a nitrogen source and Co(OAc)2•4H2O as a metal precursor by a simple chemical method. Meanwhile, in order to optimize the ORR activity, the catalysts were synthesized with different amounts of Co …


Core-Shell Pd@Pt Ultrathin Nanowires As Durable Oxygen Reduction Electrocatalysts, Xin WANG, Yun-jie XIONG, Liang-liang ZOU, Qing-hong HUANG, Zhi-qing ZOU, Hui YANG 2017 Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China;University of Chinese Academy of Sciences, Beijing 100039, China;ShanghaiTech University, Shanghai 201210, China;

Core-Shell Pd@Pt Ultrathin Nanowires As Durable Oxygen Reduction Electrocatalysts, Xin Wang, Yun-Jie Xiong, Liang-Liang Zou, Qing-Hong Huang, Zhi-Qing Zou, Hui Yang

Journal of Electrochemistry

This paper describes a simple CO-assisted reduction approach for the controllable synthesis of ultrathin Pd nanowires along the one-dimensional (1D) direction. Ultrathin Pt films from one to several atomic layers were successfully decorated onto ultrathin Pd nanowires by utilizing Cu UPD deposition, and followed by in-situ redox replacement reaction of UPD Cu by Pt. The core–shell structure and composition of the Pd@Pt ultrathin nanowires have been verified using transmission electron microscopy and energy dispersive X-ray spectrometry. The core–shell Pd@Pt ultrathin nanowires exhibited comparative electrocatalytic activity and improved durability for the oxygen reduction reaction in comparison with commercial Pt black. The …


Effect Of Allyl Thiourea On Nickel Electrodeposition From Solution Containing Ammonia And Chloride, Ya-ning HE, Liang YUAN, Zhi-ying DING, Shi-jun LIU 2017 School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Huanan,China;

Effect Of Allyl Thiourea On Nickel Electrodeposition From Solution Containing Ammonia And Chloride, Ya-Ning He, Liang Yuan, Zhi-Ying Ding, Shi-Jun Liu

Journal of Electrochemistry

The effects of allylthiourea (ATU) concentration on the cathodic polarization behaviour, nucleation and surface morphology of nickel electrodeposited on the glassy carbon electrode from ammonia-ammonium chloride-water (NH3-NH4Cl-H2O) solutions were investigated by cyclic voltammogry, cathodic polarization and current transient methods. The results revealed that the addition of ATU inhibited nickel deposition, which was enhanced with an increase in ATU concentration from 5 to 50 mg•L-1. The initial deposition kinetics corresponded to a model including instantaneous nucleation and diffusion controlled growth. In the presence of ATU, the initial nucleation of nickel electrocrystallisation remained unchanged. …


Effects Of Jet Milling And Classifying Process On The Performance Of Lifepo4/C In Full Batteries, Xing-liang LIU, Mao-ping YANG, Wei-wei WANG, Yong CAO 2017 Hefei Guoxuan High-tech Power Energy Co.,Ltd, Hefei, Anhui 230011, China;

Effects Of Jet Milling And Classifying Process On The Performance Of Lifepo4/C In Full Batteries, Xing-Liang Liu, Mao-Ping Yang, Wei-Wei Wang, Yong Cao

Journal of Electrochemistry

The carbon coated lithium iron phosphate (LiFePO4/C) composite cathode material was prepared by using iron phosphate process. The effects of jet milling and classifying process on the electrochemical performance of LiFePO4/C cathode material in full batteries were investigted. Scanning electron microscopic analyses suggested that the globose secondary particles were crustily crushed during the jet milling and classifying process, which would further result in lower tap density and carbon content. The LiFeP4/C composite cathode materials with different physical characteristics were further tested in full batteries to evaluate the electrochemical properties. The results showed no obvious …


Engineering The Electrochemical Capacitive Properties Of Activated Carbon By Correct Selection Of Ionic-Liquid Electrolytes, Qiu-hong ZHANG, Bao-shou SHEN, Song-lin ZUO, Xin-yu WEI 2017 Jiangsu Key Laboratory of Biomass-based Green Fuels and Chemicals, College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037,China;

Engineering The Electrochemical Capacitive Properties Of Activated Carbon By Correct Selection Of Ionic-Liquid Electrolytes, Qiu-Hong Zhang, Bao-Shou Shen, Song-Lin Zuo, Xin-Yu Wei

Journal of Electrochemistry

In order to improve the electrochemical capacitive properties and to apply coconut shell activated carbon (AC) serving as electrode materials in ionic liquid (IL)-based supercapacitor (SC), the coconut shell AC material was re-activated using a steam as an activating agent in this work, forming a secondary AC (W-AC). The results showed that the specific capacitance of the W-AC electrode was much larger than that of the raw activated carbon electrode (R-AC) in 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]BF4). The electrochemical techniques including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) measurement, and electrochemical impedance spectroscopy (EIS) were used to systematically study the capacitive …


Effect Of Fe2+/Fe3+Interconvertion On Reduction Behavior Of Fe3+ In Acidic Electrolytes, Jian-xin QIN, Feng LIN, Wen-ping LIU, Chao CHEN, Meng-de REN 2017 Guangxi Key Laboratory of Super-hard Material, National Special Mineral Materials Engineering Technology Research Center, China Nonferrous Metals (Guilin) Geology and Mining Co., Ltd. Guilin 541004, China;

Effect Of Fe2+/Fe3+Interconvertion On Reduction Behavior Of Fe3+ In Acidic Electrolytes, Jian-Xin Qin, Feng Lin, Wen-Ping Liu, Chao Chen, Meng-De Ren

Journal of Electrochemistry

The influences of ferrous/ferric (Fe2+/Fe3+) interconvertion on electrochemical reduction and electrode reaction of Fe3+ were investigated by using linear sweep voltammetry, potentiostatic method and cyclic voltammetry (CV) in acidic electrolytes containing chloride ion (Cl-) and sulfate ion (SO42-). It was shown that the reduction process of Fe3+/Fe2+ would take place in two independent stages: (1) the reduction of Fe3+ to Fe2+ at E=0.35V and (2) the co-precipitation of Fe2+ by forming Fe(OH)2 (E≤-0.3 V) instead of Fe. The major effect of Fe2+ …


Effect Of Calcium On Atmospheric Corrosion Resistance Of Bridge Steel, Dong-liang LI, Gui-qin FU, Miao-yong ZHU 2017 School of Metallurgy, Northeastern University, Shenyang 110819, China;

Effect Of Calcium On Atmospheric Corrosion Resistance Of Bridge Steel, Dong-Liang Li, Gui-Qin Fu, Miao-Yong Zhu

Journal of Electrochemistry

The corrosion behavior of bridge steel in simulated hot and humid industrial-marine atmosphere was investigated by mass loss analysis, XRD, SEM, electrochemical methods and a wet/dry alternate immersion corrosion test using 0.1 mol•L-1 NaCl+0.01 mol•L-1 NaHSO3 solutions. The corrosion depth (W) of experimental steels before and after calcium treatment versus time (t) curves showed a good agreement with the power function of W=Atn. The corrosion products were mainly composed of amorphous phase and a small amount of crystals including α-FeOOH, β-FeOOH, γ-FeOOH and Fe3O4. Trace calcium could promote the formation of …


Electrochemical Behaviors Of Ce3+/Ce4+ Couple In A Mixed-Acid Medium Of Ch3So3H And H2So4, Zhao-hua LI, Jiao-long XU, Ting WU 2017 Research and Development Department, Lingbao JinYuan ZhaoHui Copper Co., Ltd, Lingbao 472500, Henan, China;

Electrochemical Behaviors Of Ce3+/Ce4+ Couple In A Mixed-Acid Medium Of Ch3So3H And H2So4, Zhao-Hua Li, Jiao-Long Xu, Ting Wu

Journal of Electrochemistry

In order to determine the optimum molar ratio between methanesulfonic acid (MSA) and sulfuric acid, linear sweep voltammetry (LSV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical behaviors of cerium (III)/cerium (IV) (Ce3+/Ce4+couple on a Pt electrode in a mixed acid solution. Various concentrations of sulfuric acid were considered in the experiments, while the concentration of MSA was fixed at 1.0 mol·L-1. It was found that the optimum concentration of sulfuric acid was 0.8 mol·L-1 since the current response was the highest in the control groups and …


Preparation Of Nis2 Nanosheet And Its Application In Asymmetric Supercapacitor, Yuan-you Wang, Ya-nan Liu, Dang-qin JIN 2017 Department of Chemical Engineering, Yangzhou Polytechnic Institute, Yangzhou, 225127;

Preparation Of Nis2 Nanosheet And Its Application In Asymmetric Supercapacitor, Yuan-You Wang, Ya-Nan Liu, Dang-Qin Jin

Journal of Electrochemistry

In this work, the NiS2 nanosheets have been synthesized using Ni(OH)2  as a precursor through a sacrificial template method. The microstructure and chemical composition of as-prepared NiS2 were characterized by XRD, EDS, BET, SEM and TEM techniques. The results showed that both Ni(OH)2  and NiS2  were composed of nanoplates. The electrochemical tests revealed that NiS2 exhibited the high specific capacitance of 1067.3 F•g-1 at a current density of 1 A•g-1 and excellent rate performance. Furthermore, in order to evaluate the practical application of NiS2, an asymmetric supercapacitor, NiS2 as …


Applications Of N-Methyl-N-Butyl-Pyrrolidinium Bromide And N-Methyl-N-Ethyl-Pyrrolidinium Bromide In Zn-Br Flow Batteries, Qi ZHANG, Miao-miao ZHANG, Lin MENG 2017 Qinghai ZBEST New Energy Co.,Ltd, Haidong810600, Qinghai, China;

Applications Of N-Methyl-N-Butyl-Pyrrolidinium Bromide And N-Methyl-N-Ethyl-Pyrrolidinium Bromide In Zn-Br Flow Batteries, Qi Zhang, Miao-Miao Zhang, Lin Meng

Journal of Electrochemistry

It is extremely important for battery performance and safety in Zn-Br flow battery to use quaternary ammonium salts as complex agents for bromine. In this work, the effects of electrolyte compositions and concentrations on the electrode reactions and battery performances were studied in the absence and presences of N-methyl-N-ethyl-pyrrolidinium bromide (MEP) or N-methyl-N-butyl-pyrrolidinium bromide (MBP). The conductivities in the electrolytes containing different constitutions and concentrations were measured by EIS method. The charge-discharge performance for the battery and the complex ability for bromine in different electrolytes were also investigated. The results showed that the electrolyte containing MBP was better than that …


Kinetics And Mechanism Toward Electrochemical Reductions Of Sodium Bromide And Methanol Over Iron Electrodes, Qun LIAO, Shu-feng ZHANG, Wen-hua LENG 2017 Department of Chemistry,Zhejiang University, Hangzhou 310027, Zhejiang, China

Kinetics And Mechanism Toward Electrochemical Reductions Of Sodium Bromide And Methanol Over Iron Electrodes, Qun Liao, Shu-Feng Zhang, Wen-Hua Leng

Journal of Electrochemistry

It is of technological value and scientific interest to the electro-synthesis of ferrocene, conversion of carbon dioxide (CO2) and organic electro-synthesis in non-aqueous solutions by investigating the kinetics and mechanism toward electrochemical reductions of sodium bromide (NaBr) and methanol over iron electrodes. However, few reports in the related researches are available. In this article, the kinetics and mechanism toward electrochemical reductions of NaBr and methanol over iron electrodes were examined in detail by carrying out the polarization curve and electrochemical impedance spectroscopic measurements. The results showed that methanol was the reactant, while Na+ ions were functioned only …


Effect Of Peg-Coating On Properties Of Lithium-Sulfur Battery Cathode Material Containing Carbon Fiber Conductive Agent, Jie-cheng TAN, Yan-hong TIAN, Xue-jun ZHANG, Kai-le FAN 2017 State Key Laboratory of Organic-lnorganic Composite, College of Materials Scienee and Engineering, Beijing University of Chemical Technology, Beijing 100029, China

Effect Of Peg-Coating On Properties Of Lithium-Sulfur Battery Cathode Material Containing Carbon Fiber Conductive Agent, Jie-Cheng Tan, Yan-Hong Tian, Xue-Jun Zhang, Kai-Le Fan

Journal of Electrochemistry

The composite materials contained high modulus carbon fiber (HMCF) were successfully prepared by employing a ball-milling process based on the coating treatment of polyethylene glycol (PEG), and their structures and morphologies were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques.The influences of PEG content on sulfur cathode capacity, cycle stability and rate performance were systematically studied. It was found that by the pre-coating of PEG, the cathode exhibited the high initial discharge specific capacity of 1312.5 mAh⋅g-1 at a current rate of 0.2C, and the reversible discharge capacity of 650 mAh⋅g …


Capacity Fading Analyses Of Lini0.5Co0.2Mn0.3O2And Lini0.5Co0.2Mn0.3O2/Lifepo4 Cathode Materials For Lithium-Ion Battery, Yi HU, Xiang-zhu HE, Zhong-de DENG, Ling-yong KONG, Wei-li SHANG 2017 School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou510006, Guangdong, China;

Capacity Fading Analyses Of Lini0.5Co0.2Mn0.3O2And Lini0.5Co0.2Mn0.3O2/Lifepo4 Cathode Materials For Lithium-Ion Battery, Yi Hu, Xiang-Zhu He, Zhong-De Deng, Ling-Yong Kong, Wei-Li Shang

Journal of Electrochemistry

The LiNi 0.5Co 0.2Mn 0.3O2/LiFePO4 (NMC532/LFP) composite cathode material for lithium-ion battery was prepared by wet ball-milling. The capacity fading behaviors of LiNi 0.5Co 0.2Mn 0.3O2 (NMC532) and LiNi 0.5Co 0.2Mn 0.3O2/LiFePO4 (NMC532/LFP) were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), charge/discharge and electrochemical impedance spectroscopy (EIS) tests. The results indicated that the capacity retention values of NMC532/LFP were 97.80% and 86.48%, respectively, after 50 cycles and 60℃ high temperature storage. The NMC532/LFP exhibited better cycle performance and high temperature storage performance. …


Quantum Chemical Studies Of Noncovalent Interactions And Multicenter Bonds Utilizing Local Vibrational Modes, Vytor Oliveira 2017 Southern Methodist University

Quantum Chemical Studies Of Noncovalent Interactions And Multicenter Bonds Utilizing Local Vibrational Modes, Vytor Oliveira

Chemistry Theses and Dissertations

Noncovalent interactions play an important role for the design of novel drugs, better catalysts, synthesis of complex supramolecular structures, and so on. To develop new materials, a well-founded knowledge of how to control the strength of these interactions is desirable. Despite the many investigations done so far, a quantitative assessment of the intrinsic strength of most types of noncovalent interactions is still missing. Recently and for the first time, the Konkoli-Cremer local modes analysis was successfully used to probe the intrinsic strength of hydrogen and pnicogen bonds. We extended these investigations to more than 300 halogen and chalcogen bonds. A …


Synthesis, Characterization, And Spectroscopy Of Donor-Acceptor Charge Transfer Complexes, Dominic Kofi Kersi 2017 University of New Mexico

Synthesis, Characterization, And Spectroscopy Of Donor-Acceptor Charge Transfer Complexes, Dominic Kofi Kersi

Chemistry and Chemical Biology ETDs

A series of square-planar metal (diimine)(dichalcogenolene) chromophoric complexes have been synthesized, characterized and studied spectroscopically. Studies conducted on diimineplatinum(II) dichalcogenolene complexes (LPtL’) using time resolved spectroscopic techniques such as transient absorption and emission, reveal a charge-separated excited state of the type dichalcogenolene → diimine charge-transfer (LL’CT) [(dichalcogenolene•+)Pt(diimine•-) with an open shell donor-acceptor biradical character. This makes the low-energy ligand-to-ligand charge-transfer (LL’CT), or the mixed-metal ligand-to-ligand charge-transfer (MMLL’CT), transitions of diimineplatinum(II) dichalcogenolene complexes particularly interesting to us in facilitating our knowledge of biradical charge-separated states. Long-live excited state lifetimes were observed for these complexes upon visible photoexcitation …


Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin 2017 University of Louisville

Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin

Electronic Theses and Dissertations

Gas analysis is an important part of our world and gas sensing technology is becoming more essential for various aspects of our life. A novel approach for gas mixture analysis by using portable gas chromatography in combination with an array of highly integrated and selective metal oxide (MOX) sensors has been studied. We developed a system with small size (7 x 13 x 16 inches), low power consumption (~10 W) and absence of special carrier gases designed for portable field analysis (assuming apriori calibration). Low ppb and even sub-ppb level of detection for some VOCs was achieved during the analysis …


Eigenstate–Specific Temperatures In Two–Level Paramagnetic Spin Lattices, Mark Masthay, Calley N. Eads, Amber N. Johnson, R. Gerald Keil, Phillip Miller, Ross E. Jones, Joe D. Mashburn, Harry B. Fannin 2017 University of Dayton

Eigenstate–Specific Temperatures In Two–Level Paramagnetic Spin Lattices, Mark Masthay, Calley N. Eads, Amber N. Johnson, R. Gerald Keil, Phillip Miller, Ross E. Jones, Joe D. Mashburn, Harry B. Fannin

Chemistry Faculty Publications

Increasing interest in the thermodynamics of small and/or isolated systems, in combination with recent observations of negative temperatures of atoms in ultracold optical lattices, has stimulated the need for estimating the conventional, canonical temperature Tconvc of systems in equilibrium with heat baths using eigenstate-specific temperatures (ESTs). Four distinct ESTs—continuous canonical, discrete canonical, continuous microcanonical, and discrete microcanonical—are accordingly derived for two-level paramagnetic spin lattices (PSLs) in external magnetic fields. At large N, the four ESTs are intensive, equal to Tconvc, and obey all four laws of thermodynamics. In contrast, for N < 1000, the ESTs of most PSL eigenstates are non-intensive, differ from Tconvc, and violate each of the thermodynamic laws. Hence, in spite of their similarities to Tconvc at large N, the ESTs …


Surface And Interface Characterization Of Solution-Processed Metal Oxides And Pedot:Pss Using Photoelectron Spectroscopy, Lynette M. Kogler 2017 University of Nevada, Las Vegas

Surface And Interface Characterization Of Solution-Processed Metal Oxides And Pedot:Pss Using Photoelectron Spectroscopy, Lynette M. Kogler

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solution-processed materials are appealing for use in printable electronics as a means to lower production costs, but precise control of the process is crucial for achieving the desired properties in the final materials and their interfaces. Electronic interface properties depend on both the involved materials and their fabrication processes, impacting the development and commercialization of these materials. Analyzing the chemical and electronic structure of these materials, particularly at the surfaces and interfaces, is important not only for insuring that the materials have the desired properties, but also for understanding the effects of the fabrication process and how to modify properties …


The Electrochemical Deposition Of Samarium And Europium Dissolved In Ionic Liquid Solvent, Bea Martinez 2017 University of Nevada, Las Vegas

The Electrochemical Deposition Of Samarium And Europium Dissolved In Ionic Liquid Solvent, Bea Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rare-earth elements include the lanthanide series in the periodic table with the addition of scandium and yttrium. China produces approximately 95% of the world’s rare-earths supply and is the largest consumer of the world’s rare earth supply. Domestic production of rare-earth metals is a priority in the US. The domestic demand for rare-earth elements is largely based on their use in electronic devices, catalytic converters, and more importantly defense applications. Therefore, China’s monopoly of rare-earth elements is viewed as a threat to national security. Although capital investments have resulted in an increase in domestic mining and refining of rare-earth materials, …


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