Polarographic behaviour of metals in ethanolamines

Subrahmanya, R. S.

doi:10.1007/bf03052759

Cited by 17 publications

(4 citation statements)

References 10 publications

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“…log a± for carbonate ion gives a slope of -0.092 in agreement with the theoretical value of -0.090 for the complex. Formation of mixed ligand type amine carbonato complexes of cadmium(II),234 zinc(II),235 cobalt(II),236 nickel(II),237 iron(II), 238 and iron(III)288 has been reported in a series of papers. They have the general formulas, [M(Moen)-C03]0, [M(Dien)C03]0, [M(Trien)C03]°, and [M(Amine)-(C03)Ji2-2z) ~, where M is a bipositive metal, Moen = monoethanolamine, Dien = diethanolamine, and Trien = tri- e. Potentiometric Method…”

Section: Ion-exchange Methodsmentioning

confidence: 98%

Chemistry of the metal carbonato complexes

Krishnamurty¹,

Harris²,

Sastri³

1970

Chem. Rev.

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Section: Ion-exchange Methodsmentioning

confidence: 98%

Chemistry of the metal carbonato complexes

Krishnamurty¹,

Harris²,

Sastri³

1970

Chem. Rev.

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“…One Fe(III) apparently is complexed with one triethanolamine and with varying numbers of OH-, depending on the pH (11). After the reduction of the Fe(III) complex, a dissociation reaction involving the ferrous triethanolamine complex appears to take place (16)(17)(18).…”

Section: Theoretical Correlationsmentioning

confidence: 99%

“…For both methods of measuring id, values of ik were obtained for five scan rates ranging from 50 mv./second to 1.02 volts/second. Values of ik/id which were obtained were used with a working curve similar to Figure 14 in Reference (6), and calculated from (18) At very cathodic potentials, Equation 18reduces to a form previously presented by Saveant and Vianello (12): i = nFACo* VDkc (19) Experimental stationary electrode polarograms were obtained at 50 mv./ second under conditions where Equations 18 and 19 hold for the Fe(III)-y/Cz, and a plot of the limiting current as a function of y/Cz should be linear, with a slope proportional to yjk. This method of treating the data provided a value of the rate constant k equal to 217 (.1//Z)-1 second-1.…”

Section: Ratementioning

confidence: 99%

Theory of Stationary Electrode Polarography for a Multistep Charge Transfer with Catalytic (Cyclic) Regeneration of the Reactant.

Polcyn¹,

Shain²

1966

Anal. Chem.

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“…This was achieved by coordination of Fe with TEA and of Co with mTEA. In previous reports, complexes of these two metal ions with amino-alcohol ligands such as TEA were successfully synthesized in base and used in analytical determinations, [6][7][8] electrodeposition, 9,10 electrochemical studies, 11,12 and the reduction of dyes. [13][14][15] The Yang group has previously proposed the use of Fe-TEA as the negative redox couple in RFB studies with the Br 2 /Br − as the positive one.…”

mentioning

confidence: 99%

An Alkaline Flow Battery Based on the Coordination Chemistry of Iron and Cobalt

Arroyo‐Currás

Hall

Dick

et al. 2014

J. Electrochem. Soc.

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We present the first alkaline redox flow battery (a-RFB) based on the coordination chemistry of cobalt with 1-[Bis(2-hydroxyethyl)amino]-2-propanol (mTEA) and iron with triethanolamine (TEA) in 5 M NaOH. The overall redox system has a cell voltage of 0.93 V in the charged state. Importantly, the coordination compounds are negatively charged and have limited transport through the cation exchange membrane (e.g., Nafion), minimizing the extent of redox species crossover during charge-discharge cycling. Fe-TEA is electrochemically reversible and soluble up to 0.8 M, whereas Co-mTEA presents quasireversible electron transfer kinetics and can be solubilized up to 0.7 M. Cyclability was tested with a flow cell at a concentration 0.5 M up to 30 cycles using a 50 μm thick Nafion membrane, at 30 mA/cm 2 , with minimal crossover (less than 4% of net concentration) or evolution of gases detected. The redox flow battery (RFB) has excellent potential for electrical grid energy storage. However, it has not yet been widely deployed often because of problems of stability and limited cycle life. In this report we describe the use of coordination compounds of cobalt with 1-[Bis(2-hydroxyethyl)amino]-2-propanol (mTEA, Figure 1A), and iron with triethanolamine (TEA, Figure 1B) in 5 M NaOH as a RFB. The flow battery was optimized to achieve stable cycling with 71% average energy efficiency in 30 cycles when passing 30 mA cm −2 , and using a 50 μm-thick Nafion membrane as the separator, at a concentration 0.5 M. Importantly, crossover of the redox species through the membrane was below 5% of the original concentration at the end of the 30 th cycle, with no evolution of gases detected during cycling. We developed this alkaline RFB as an alternative to state of the art RFBs, e.g., the all vanadium RFB, which are based on acidic electrolytes.1 Acidic RFBs often suffer capacity fading due to membrane crossover and the occurrence of undesired secondary reactions during battery cycling (e.g., precipitation, evolution of H 2 and Cl 2 gases).2 Acidic electrolytes have a high conductance, G max = 825 mS cm −1 for 3 M H 2 SO 4(aq), 3 but tend to be corrosive to the cell components, which translates into high operational and maintenance costs. 4 In contrast, alkaline electrolytes such as NaOH have lower conductance, G max = 410 mS cm −1 for 3.7 M NaOH (aq) 3 , but are less corrosive. Alkaline electrolytes employing transition metals generally require the use of coordination compounds as redox species to prevent precipitation of the hydroxides or hydrous oxides. The net charge on these ions can be tailored by ligand selection to minimize membrane crossover with a cation exchange membrane. Moreover, different ligands can be used to tune the electrode potential of the half-cells to optimize the voltage of the battery. 5The formation of chemically stable soluble coordination compounds of cobalt and iron in 5 M NaOH is challenging because of a thermodynamic tendency to form their insoluble hydroxides. For iron(III), with a solubility product, K sp , ...

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Polarographic behaviour of metals in ethanolamines

Cited by 17 publications

References 10 publications

Chemistry of the metal carbonato complexes

Chemistry of the metal carbonato complexes

Theory of Stationary Electrode Polarography for a Multistep Charge Transfer with Catalytic (Cyclic) Regeneration of the Reactant.

An Alkaline Flow Battery Based on the Coordination Chemistry of Iron and Cobalt

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