Physical Sciences and Mathematics Commons^™

Cathodic Deposition Of Triangular Tungsten Clusters From Ionic Liquids: An Explorative Study, Linda N. Ubadigbo

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In the present work, the triangular tungsten clusters {[W3O2(O2CCH3)6](H2O)3}(CF3SO3)2 and {[W3O2(O2CCH2CH3)6](H2O)3}(BF4)2. 5.5H2O were dissolved in both hydrophobic and hydrophilic ionic liquids (ILs) and subjected to a cathodic potential of roughly 2V. It was proposed that successful deposition of these metal clusters on a platinum electrode would yield Pt-supported anodic catalysts which could be used in ethanol fuel cells (EFCs). Visual examination of the electrode surfaces indicated that a film had been deposited, however, the surface with W3(CF3SO3)2 quickly oxidized when removed from the IL. Therefore, SEM imaging and EDX analysis of the W3(BF4)2 surface were performed. The data indicated that …

The Synthesis Of Room-Temperature Ionic Liquids And Their Metathesis Reactions With Dilithium Phthalocyanine, Andrew Michael Beauchamp

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A series of alkoxyalkylammonium salts has been synthesized for use in metathesis reactions with dilithium phthalocyanine. The salts, which were ionic liquids at or near room temperature, were synthesized by a nucleophilic substitution of tris[2-(2-methoxyethoxy)ethyl]amine and iodomethane, iodoethane, bromoethane, 1-bromo-propane, 1-bromo-2-(2-methoxyethoxy)ethane, and [2-[2-(2-methoxyethoxy)ethoxy]-ethoxy] p-toluenesulfonate in yields ranging from 67% - 88%. The methyl, ethyl, propyl and tetra[2-(2-methoxyethoxy)ethyl]ammonium salts were obtained for use in metathesis reactions. The salts were liquid at room temperature, with the exception of tetra[2-(2-methoxyethoxy)ethyl]ammonium bromide which was found to melt at 46° and were thermally stable to approximately 200°. The four salts were used in metathesis reactions …

Thermal And Electrochemical Characterization Of Cathode Materials For High Temperature Lithium-Ion Batteries In Ionic Liquids, Jodie R. Shoaf

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Finding a cathode material to operate a high-temperature Li-ion battery in the presence of an ionic liquid has become an attractive area of research. Three cathode materials, LiCoO2, Li4Ti5O12, and LiFePO4, were received from Electrochemical Systems Inc. of Knoxville, TN. Three ionic liquids were synthesized using a 1-alkyl-3-methylimidazolium (XMI+) cation, where the alkyl group was either ethyl, pentyl or hexyl, and contained a bis(pentafluoroethylsulfonyl)imide (Beti-) anion. The thermal and electrochemical properties of each ionic liquid, of each cathode material, and each combination of cathode material in the presence of ionic liquid were studied. All of the ionic liquids were found …

1-Alkyl-3-Methylimidazolium Bis(Trifluoromethylsulfonyl)Imide Based Ionic Liquids: A Study Of Their Physical And Electrochemical Properties, Charles William Dutton

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Ionic liquids are of interest because of their electrochemical and thermal properties and their possible use as electrolytes in batteries. In this work five ionic liquids were synthesized. They consisted of a 1-alkyl-3-methylimidazolium (RMI⁺) cation, where the alkyl group was ethyl, propyl, butyl, pentyl, or hexyl, and a bis(tri-fluoromethylsulfonyl)imide (NTf2^-)anion. The decomposition temperatures, melting points, conductivities, viscosities, densities, absorption and desorption of water, diffusion coefficients, and electrochemical properties were studied. It was found that these ionic liquids were thermally stable up to ~310 °C, and that EMINTf₂ had a melting point at -18.26 °C. Conductivities …

Electrochemical Oxidation Of Ethanol In Ionic Liquids And Its Possible Use In Fuel Cells, Ashley M. Mason

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Electrochemical properties of EtOH in EMImBF4 ionic liquid were investigated and compared to the electrochemical properties of EtOH in 0.1M HClO4/H2O. As was shown earlier, oxidation of EtOH in HClO4/H2O involves formation of PtO on the electrode surface, which makes the electrode poisoned. We have found that the best procedure for removal of PtO from the Pt electrode is heating the electrode in concentrated H2SO4. Cyclic voltammograms obtained after cleaning several Pt electrodes conforms that this treatment gives clean Pt electrodes without any PtO. Electrochemical oxidation of EtOH in EMImBF4 ionic liquid show that is poisoning of Pt electrode by …

A Comparison Of Physical And Electrochemical Properties Of Two Ionic Liquids Containing Different Cations: 1-Butyl-1-Methyl-Pyrrolidinium Beti And 1-Butyl-3-Methyl-Imidazolium Beti, Edward Nelson Kennedy

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A novel ionic liquid, 1,1-butyl-methyl-pyrollidinium bis-pentafluoroehthanesulfonylamide (BMPyrrBeti) was synthesized and characterized. Its physical and electrochemical properties compared to a similar ionic liquid containing the imidazolium cation, 1-methyl-3-butyl-imidizolium bis-pentafluoroehthanesulfonylamide (BMImBeti). The two ionic liquids contain the same anion, bis((pentafluoroethane)sulfonyl)imide (Beti), and the same two alkly group substituents (a methyl and a butyl group). The two ionic liquids differ only by the cation component, and the connectivity of the two substituents (1,1 for the former, and 1,3 for the latter).

The following physical properties of BMPyrrBeti were measured and compared to the same properties of BMImBeti: conductivity, viscosity, absorption and desorption of …

Comparison Of The Electrochemical Properties Of Ethanol In Perchloric Acid And Ionic Liquids, Sandra Felix-Balderrama

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1-Ethyl-3-Methylimidazolium Tetrafluroborate (EMImBF₄) and 1-Ethyl-3-Methylimidazlium Bis(trifluoromethanesulfonyl)imide (EMImTFSI) ionic liquids were synthesized and characterized in order to study the electrochemical oxidation of ethanol in these ionic liquids on a platinum surface electrode.

It was found that pure EMImBF₄ exhibits an electrochemical window of 4.4 V,while EMImTFSI exhibits an electrochemical window of 5.0 V.

Electrochemical study of ethanol in perchloric acid showed that the oxidation of ethanol strongly depends on the concentration of ethanol and on the temperature of the solution. The poisoning of the platinum electrode only depends on the concentration of ethanol. At a low concentration of …

1-Alkyl-3-Methylimidazolium Bis(Pentafluoroethylsulfonyl)Imide Based Ionic Liquids: A Study Of Their Physical And Electrochemical Properties, Jennifer N. Decerbo

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Ionic liquids are an attractive possibility for battery electrolytes. Five ionic liquids were synthesized using a 1-alkyl-3-methylimidazolium (XMI+) cation, where the alkyl group was ethyl, propyl, butyl, pentyl, or hexyl, and a bis(pentafluoroethyl-sulfonyl)imide (Beti-) anion. The absorption and desorption of water, conductivities, densities, viscosities, decomposition temperatures, and electrochemical properties were studied. These ionic liquids were found to absorb less water than previously studied ionic liquids with tetrafluoroborate (BF4-) and hexafluorophosphate (PF6-) anions. Their conductivities decreased with longer alkyl chains on the imidazolium cation and were lower than ionic liquids with BF4- as the anion. The densities of the ionic liquids …