51V NMR and EPR Study of Reaction Kinetics and Mechanisms in V2O5 Gelation by Ion Exchange of Sodium Metavanadate Solutions

Pozarnsky, G. A.; McCormick, Alon V.

doi:10.1021/cm00040a009

Cited by 45 publications

(92 citation statements)

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“…On the other hand, if the pH of the aggressive electrolyte is greater than 4, metavanadates will be the species released and present in solution. 51 V NMR was used to determine quantitatively the speciation of vanadate solutions. Decavanadates were prepared by first acidifying clear metavanadate solutions to pH 4 and then readjusting to pH 8.71.…”

Section: Resultsmentioning

confidence: 99%

“…NMR spectroscopy.-Procedures for 51 V NMR described in the literature were followed. 39,[42][43][44][45][46][47] High-resolution 51 V (105.2 MHz)_spectra were obtained at room temperature utilizing a Bruker DPX 400 MHz superconducting magnet.…”

Section: Methodsmentioning

confidence: 99%

“…A 100 mM orange decavanadate solution adjusted to pH 8.71 was aged for 10 days. Samples were extracted for 51 V NMR analysis and electro-chemical characterization after 1, 3, and 10 days. The solution pH decreased slowly over time; therefore, pH was readjusted to 8.71 before the experiments.…”

Section: Nuclear Magnetic Resonance Spectroscopy (Nmr)-mentioning

confidence: 99%

“…50 The only limitation of NMR is the inability of detecting minor components with overlapping or coincident chemical shifts. 50 According to 51 V and 17 O NMR spectroscopy, the observed oligomers in the range of pH 7-9 and at varied vanadate concentrations are the monovanadates (V 1 ), divanadates (V 2 ), cyclic tetravanadates (V 4 ), and cyclic pentavanadates (V 5 ). [42][43][44] In contrast, decavanadates are stable in the pH range from 2 to 6 but can form in solutions of higher pH due to local acidification of the solution.…”

mentioning

confidence: 99%

“…The main objective of this work is to understand which vanadate oligomer imparts the best corrosion protection for AA2024-T3. Vanadate speciation as a function of pH and concentration is investigated by 51 V NMR. The influence of decavanadate formation, solution aging, and bulk pH on corrosion inhibition of AA2024-T3 is also addressed.…”

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confidence: 99%

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Aluminum Alloy Corrosion Inhibition by Vanadates

Iannuzzi¹,

Young

Frankel³

2006

J. Electrochem. Soc.

108

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The inhibition of Al alloy corrosion by vanadates was studied in this work. Vanadium speciation is very complicated and vital to the inhibition efficacy. Critical conditions for decavanadate polymerization from clear metavanadate solutions were investigated. Decavanadate only formed when metavanadate was added to solutions of pH 3 or less. It was not possible to change the pH of a metavanadate solution without forming decavanadates, creating an orange-colored solution. According to 51 V nuclear magnetic resonance, monovanadates were present only in clear metavanadate solutions; orange solutions always contained decavanadates and never contained monovanadates. Orange decavanadate solutions containing 0.5 M NaCl at pH 8.71 exhibited no significant inhibition of the oxygen reduction reaction and increasing decavanadate concentration was detrimental. In contrast, clear metavanadate solutions containing monovanadate exhibited strong inhibition of the oxygen reduction reaction, to a level similar to chromate. At a fixed pH, increased NaVO 3 concentration in clear metavanadate solutions increased inhibition efficiency.High-strength aluminum alloys are used widely in structural aircraft applications because of the combination of good mechanical properties and light weight.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Nuclear Magnetic Resonance Spectroscopy (Nmr)-mentioning

confidence: 99%

mentioning

confidence: 99%

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confidence: 99%

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Aluminum Alloy Corrosion Inhibition by Vanadates

Iannuzzi¹,

Young

Frankel³

2006

J. Electrochem. Soc.

108

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A Cuboctahedral Supramolecular Capsule by 4:4 Self-Assembly of Tris(ZnII-cyclen) and Trianionic Trithiocyanurate in Aqueous Solution at Neutral pH (Cyclen=1,4,7,10-Tetraazacyclododecane)

Aoki¹,

Shiro²,

Kimura³

2002

Chem. Eur. J.

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Large‐scale electrical energy storage has become more important than ever for reducing fossil energy consumption in transportation and for the widespread deployment of intermittent renewable energy in electric grid. However, significant challenges exist for its applications. Here, the status and challenges are reviewed from the perspective of materials science and materials chemistry in electrochemical energy storage technologies, such as Li‐ion batteries, sodium (sulfur and metal halide) batteries, Pb‐acid battery, redox flow batteries, and supercapacitors. Perspectives and approaches are introduced for emerging battery designs and new chemistry combinations to reduce the cost of energy storage devices.

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