Estimation of the composition of intermetallic compounds in LiCl–KCl molten salt by cyclic voltammetry

2016 ◽  
Vol 190 ◽  
pp. 387-398 ◽  
Author(s):  
Ya L. Liu ◽  
Kui Liu ◽  
Li Y. Yuan ◽  
Zhi F. Chai ◽  
Wei Q. Shi
Keyword(s):  
Cyclic Voltammetry ◽  
Molten Salt ◽  
Intermetallic Compounds ◽  
Reduction Process ◽  
Reduction Processes ◽  
Cv Measurements ◽  
Co Reduction

In this work, the compositions of Ce–Al, Er–Al and La–Bi intermetallic compounds were estimated by the cyclic voltammetry (CV) technique. At first, CV measurements were carried out at different reverse potentials to study the co-reduction processes of Ce–Al, Er–Al and La–Bi systems. The CV curves obtained were then re-plotted with the current as a function of time, and the coulomb number of each peak was calculated. By comparing the coulomb number of the related peaks, the compositions of the Ce–Al, Er–Al and La–Bi intermetallic compounds formed in the co-reduction process could be estimated. The results showed that Al11Ce3, Al3Ce, Al2Ce and AlCe could be formed by the co-reduction of Ce(iii) and Al(iii). For the co-reduction of Er(iii) and Al(iii), Al3Er2, Al2Er and AlEr were formed. In a La(iii) and Bi(iii) co-existing system in LiCl–KCl melts, LaBi2, LaBi and Li3Bi were the major products as a result of co-reduction.

scholarly journals Suitability of the Cyclic Voltammetry Measurements and DPPH• Spectrophotometric Assay to Determine the Antioxidant Capacity of Food-Grade Oenological Tannins

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2925 ◽  
Author(s):  
Arianna Ricci ◽  
Giuseppina Paola Parpinello ◽  
Nemanja Teslić ◽  
Paul Andrew Kilmartin ◽  
Andrea Versari
Keyword(s):  
Cyclic Voltammetry ◽  
Colorimetric Assay ◽  
Radical Scavenging ◽  
Calibration Graph ◽  
Spectrophotometric Assay ◽  
Experimental Conditions ◽  
Fast Analysis ◽  
Cv Measurements ◽  
And Control ◽  
Analytical Approaches

Twenty commercially available oenological tannins (including hydrolysable and condensed) were assessed for their antiradical/reducing activity, comparing two analytical approaches: The 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging spectrophotometric assay and the cyclic voltammetry (CV) electrochemical method. Electrochemical measurements were performed over a −200 mV–500 mV scan range, and integrated anodic currents to 500 mV were used to build a calibration graph with (+)-catechin as a reference standard (linear range: From 0.0078 to 1 mM, R2 = 0.9887). The CV results were compared with the DPPH• assay (expressed as % of radical scavenged in time), showing high correlation due to the similarity of the chemical mechanisms underlying both methods involving polyphenolic compounds as reductants. Improved correlation was observed by increasing the incubation time with DPPH• to 24 h (R2 = 0.925), demonstrating that the spectrophotometric method requires a long-term incubation to complete the scavenging reaction when high-molecular weight tannins are involved; this constraint has been overcome by using instant CV measurements. We concluded that the CV represents a valid alternative to the DPPH• colorimetric assay, taking advantage of fast analysis and control on the experimental conditions and, because of these properties, it can assist the quality control along the supply chain.

scholarly journals Metal reduction by hydrogen from the B2O3-СaO-Ni(Zn, Pb, Cu)O melts thermodynamic modeling

2020 ◽  
Vol 61 (2) ◽  
pp. 145-151
Author(s):  
Alexander S. Vusikhis ◽  
◽  
Evgeny N. Selivanov ◽  
Stanislav N. Tyushnyakov ◽  
Viktor P. Chentsov ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Thermodynamic Modeling ◽  
Reduction Process ◽  
Reducing Agent ◽  
Metal Reduction ◽  
Oxide Melt ◽  
Reduction Processes ◽  
Lead And Zinc ◽  
Nickel Copper ◽  
Copper Lead

Thermodynamic modeling is used to describe the metal reduction processes by hydrogen from oxide melt in the B2O3-CaO- MeO (Me – Ni, Zn, Pb, Cu) system. Open systems approximation with periodic removal of metal particles and gases from the working melt composition is used in the method. By this work we present the thermodynamic modeling results of metal reduction processes (Ni, Cu, Pb, Zn) by Hydrogen. The reducible metals oxides content in the all melts was 3 mass %, and the mass ratio of B2O3/CaO was taken as 3 to be close to eutectic composition. The calculations made it possible to determine such parameters as oxide melt compositions and elements reduction degree depending on the induced gas quantity. of the Nickel, Copper, Lead and Zinc reduction process simulation from B2O3-CaO-MeO melts proved the reduction process by Hydrogen is similar to that which was earlier established when Carbon monoxide was used as the reducing agent. When Copper is reduced from CuO, the process occurs with intermediate Cu2O oxide formation (CuO → Cu2O → Cu). The Nickel (NiO → Ni), Lead (PbO → Pbs + Pbg) and Zinc (ZnO → Zng) recovery have been realized by one stage. The non-ferrous metals change content in the oxide melt and the degrees of its reduction depending on temperature and reducing agent quantity introduced are described by the second-order polynomial functional equations. Comparison of the Carbon monoxide and Hydrogen used for Nickel, Copper, Lead, and Zinc reducing to 90% metallization degree proved much less Hydrogen consumption.

scholarly journals Síntesis regioespecífica y estudio electroquímico de dos derivados carboxílicos C60 solubles en agua

2021 ◽  
Author(s):  
Juan D. Villada ◽  
Álvaro Duarte-Ruiz ◽  
Manuel N. Chaur
Keyword(s):  
Cyclic Voltammetry ◽  
Liquid Chromatography ◽  
Electronic Properties ◽  
Reaction Times ◽  
C60 Fullerene ◽  
Reduction Processes ◽  
Vis Spectroscopy ◽  
Highperformance Liquid Chromatography ◽  
Electron Transfers ◽  
Reversible Reduction

We report a new methodology for the synthesis of two highly symmetric equatorial malonate hexaadducts of C60 fullerene. The synthetic methodology is based on a series of protection and deprotection steps that allow the preparation of a fullerene [60] functionalized with six symmetrical positioned malonate addends without using complicated and expensive separation techniques (highperformance liquid chromatography, HPLC) or long reaction times. This methodology allowed us to prepare the carboxylic adducts 6 (equatorial octacarboxylic tetraadduct of C60) and 8 (equatorial dodecacarboxylic hexakisadduct of C60). As far as we  now, compound 6 has not yet been reported. We also studied the electronic properties of the main compounds by UV-Vis spectroscopy and cyclic voltammetry (CV). The reported fullerene adducts exhibited several reversible reduction processes whose electron transfers are controlled by diffusion. 

Design and synthesis of dichromeno[2,3-b;3′,2′-e]pyridine-12,14-dione to evaluate its optical properties

2017 ◽  
Vol 41 (10) ◽  
pp. 3887-3893 ◽  
Author(s):  
Pritam Biswas ◽  
Jaydip Ghosh ◽  
Tapas Sarkar ◽  
Debabrata Jana ◽  
Chandrakanta Bandyopadhyay
Keyword(s):  
Cyclic Voltammetry ◽  
Optical Properties ◽  
Thermogravimetric Analysis ◽  
Dft Calculations ◽  
Design And Synthesis ◽  
Mild Conditions ◽  
Cv Measurements

An unambiguous synthesis of dichromeno[2,3-b;3′,2′-e]pyridine-12,14-diones has been developed under mild conditions and their optical properties have been evaluated by studying UV-vis absorption and photoluminescence (PL) spectroscopy, cyclic voltammetry (CV) measurements, DFT calculations and thermogravimetric analysis.

scholarly journals Electrodeposition Behavior of Polycrystalline Ni–Mo–La Composite in Alkaline Solution

Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 299 ◽  
Author(s):  
Ning Li ◽  
Weizeng Chen ◽  
Lirong Lu ◽  
Chenghui Gao
Keyword(s):  
Cyclic Voltammetry ◽  
Alkaline Solution ◽  
Reduction Potential ◽  
Structural Phase ◽  
Reduction Process ◽  
Deposition Process ◽  
Nickel Ions ◽  
Ionic Activity ◽  
Lanthanum Ions ◽  
Metal Atoms

The polycrystalline Ni–Mo–La composite coating was obtained by electrodeposition through the addition of La3+ ions into Ni, Mo ions main salt weak alkaline solution. The obtained composite contain 0.92 at.% La. According to the law of ionic activity, the redox reaction of three kinds of metal atoms was studied by polarography and cyclic voltammetry. It was found that the addition of lanthanum ions changed the composite structural, phase, and element, and the OH− ions were deduced during the electrodeposition in alkaline solution. The introduction of lanthanum and molybdenum ions negatively shifted the reduction potential of nickel ions and broadened the peaks significantly in the deposition process, retarding the reduction and deposition rate of Ni ions, which was characterized by a multi-step reduction process of Mo and La metal atoms.

An experimental study for Li recycling in an electrolytic reduction process for UO2 with a Li2O–LiCl molten salt

2013 ◽  
Vol 441 (1-3) ◽  
pp. 232-239 ◽  
Author(s):  
Wooshin Park ◽  
Jin-Mok Hur ◽  
Sun-Seok Hong ◽  
Eun-Young Choi ◽  
Hun Suk Im ◽  
...  
Keyword(s):  
Experimental Study ◽  
Molten Salt ◽  
Reduction Process ◽  
Electrolytic Reduction

An Effect of Bismuth Ion on the Reduction of Terbium Ion in Molten LiCl-KCl Eutectic Salt

2018 ◽  
Author(s):  
Beom Kyu Kim ◽  
Byung Gi Park ◽  
Hwa Jeong Han ◽  
Ji Hye Park ◽  
Won Ki Kim
Keyword(s):  
Intermetallic Compound ◽  
Electrochemical Techniques ◽  
Reduction Process ◽  
Open Circuit ◽  
Cyclic Voltammograms ◽  
Reduction Peak ◽  
Cyclic Voltammogram ◽  
Square Wave ◽  
Co Reduction ◽  
Salt Waste

A salt waste generated from the pyroprocess contains residual actinides and needs to be purified for recycling of the salt and waste conditioning. A co-reduction process could be considered for removal of residual actinides from the salt waste, which contains lanthanides and residual actinides. In the study, specifically, an effect of Bi(III) ion on the electrochemical reaction of Tb(III) ion was investigated in the molten LiCl-KCl eutectic with BiCl3 and TbCl3 at 773 K using electrochemical techniques of cyclic voltammetry, square wave voltammetry and open circuit chronopotentiometry. Tb(III) has a single redox couple without Bi(III). However, the cyclic voltammograms obtained at tungsten electrode in LiCl-KCl-BiCl3-TbCl3 showed four redox couples. The square wave voltammogram in same condition also showed five reduction peaks. Cyclic voltammogram and square wave voltammogram was resolved to find the accurate peaks for redox reaction. Each peak indicates the formation of Tb-Bi intermetallic compound except Tb(III) reduction peak. From the phase diagram of Tb-Bi, it is inferred that each peak corresponds to TbBi2, TbBi, Tb4Bi3, and Tb5Bi3. The open circuit chronopotentiometry was conducted to estimate Gibbs free energy of formation of Tb-Bi intermetallic compound. The experimental results obtained from three kind of the electrochemical techniques showed that Tb-Bi intermetallic compounds were electrochemically formed under potential of Tb(III) reduction potential by co-reduction of Bi(III) and Tb(III). These results indicate that underpotential deposition by co-reduction could be used for Tb(III) removal from the salt waste with Bi(III).

Study on Cyclic Voltammetry in Na3AlF6-Al2O3-LiF Molten Salt Electrolysis

2013 ◽  
Vol 746 ◽  
pp. 101-105
Author(s):  
Shao Hu Tao ◽  
Yue Zhong Di ◽  
Jian Ping Peng ◽  
Kun Zhao ◽  
Nai Xiang Feng
Keyword(s):  
Cyclic Voltammetry ◽  
Molten Salt ◽  
Xrd Analysis ◽  
Electrochemical Process ◽  
Single Step ◽  
Molar Ratio ◽  
Al Alloy ◽  
Tungsten Electrode ◽  
Molten Salt Electrolysis ◽  
Cr System

Electrochemistry reaction of the Al3+ by means of cyclic voltammetry. The results show that the Al3+ was reduced to Al metal in a single step. During the electrochemical process, metal Na and Li did not deposit out on tungsten electrode. After adding LiF, the oxidation peak of Al was weakened and the oxidation quality of Al decreased. Compared with cyclic voltammetry curves at different CR ratio (CR=molar ratio of NNaF/NAlF3 in the bath), LiF is more effective in the low CR system for electrolyte. The XRD analysis shows that Li-Al alloy was soluble in the molten salt while Li + and Al3+occured alloying reaction.

Sign in / Sign up

Export Citation Format

Share Document