Investigation of oxidation processes at metal oxide electrodes
Investigation of oxidation processes at metal oxide electrodes
In aqueous media have been studied at tungsten, bronze, electrodes of five compositions (Na xWO3, 0.9>x>0.4). It has been'' shown that the reactions are simple electron transfer processes and the standard heterogeneous rate constants, determined by cyclic voltammetry, are lower than at Pt or Hg and vary only slightly with these composition of the bronze. These mixed metal oxides are also shown to be good electrodes in aprotic media and the cyclic voltammetry of a series of polynuclear hydrocarbons is very similar to that at Hg or Pt.The mechanism and application of electrode reactions at several types of metal oxide electrode have been investigated. The couples Fe(CN4 /Fe(CN)6 and Fe (oxalate)3 I Fe(oxalate)3Ielectrodes.The electro-chemistry of a nickel oxide electrode in alkaline tertiary butanol/water mixtures has been, studied. A range of benzyl alcohols, phenylethanols and allyl alcohols give well formed but kinetically controlled oxidation waves at the potential of the Ni II/NiIII surface change in these media. Hence it is suggested that the rate determining step is a chemical reaction between the higher nickel oxide and thee alcohol. The limiting currents are however, low. Large scale Constant current oxidations of the phenylethanols and allyl alcohols ive only carboxylic acids in good yields. The beazyl alcohols give both aldehydes and carboxylic acids although;: the total yield is high; the ratio of aldehyde/carboxylic acid may be changed dramatically by variation of the pH. The oxidation of phenylethylamine and benzylamine are mechanistically similar and lead to nitriles. It has been shown that stable lead dioxide electrodes may be prepared by deposition of the oxide onto vitreous carbon from a variety of Pb2+ solutions. The mechanism and deposition from acetate and perchlorate media is similar to that when the substrate is platinum The 3t oxidation of Cr, C103, alcohols and phenols does occur on, these electrodes but, the rate depends on the preparation and pretreatment of the surface. These electrode reactions are slow and occur by a diversity of mechanisms, both chemical and electrochemical steady state electrochemical experiments and electron microscopy were found to be the only satisfactory techniques for their study.
University of Southampton
Chaudhary, Mohammad Amjad
1976
Chaudhary, Mohammad Amjad
Chaudhary, Mohammad Amjad
(1976)
Investigation of oxidation processes at metal oxide electrodes.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
In aqueous media have been studied at tungsten, bronze, electrodes of five compositions (Na xWO3, 0.9>x>0.4). It has been'' shown that the reactions are simple electron transfer processes and the standard heterogeneous rate constants, determined by cyclic voltammetry, are lower than at Pt or Hg and vary only slightly with these composition of the bronze. These mixed metal oxides are also shown to be good electrodes in aprotic media and the cyclic voltammetry of a series of polynuclear hydrocarbons is very similar to that at Hg or Pt.The mechanism and application of electrode reactions at several types of metal oxide electrode have been investigated. The couples Fe(CN4 /Fe(CN)6 and Fe (oxalate)3 I Fe(oxalate)3Ielectrodes.The electro-chemistry of a nickel oxide electrode in alkaline tertiary butanol/water mixtures has been, studied. A range of benzyl alcohols, phenylethanols and allyl alcohols give well formed but kinetically controlled oxidation waves at the potential of the Ni II/NiIII surface change in these media. Hence it is suggested that the rate determining step is a chemical reaction between the higher nickel oxide and thee alcohol. The limiting currents are however, low. Large scale Constant current oxidations of the phenylethanols and allyl alcohols ive only carboxylic acids in good yields. The beazyl alcohols give both aldehydes and carboxylic acids although;: the total yield is high; the ratio of aldehyde/carboxylic acid may be changed dramatically by variation of the pH. The oxidation of phenylethylamine and benzylamine are mechanistically similar and lead to nitriles. It has been shown that stable lead dioxide electrodes may be prepared by deposition of the oxide onto vitreous carbon from a variety of Pb2+ solutions. The mechanism and deposition from acetate and perchlorate media is similar to that when the substrate is platinum The 3t oxidation of Cr, C103, alcohols and phenols does occur on, these electrodes but, the rate depends on the preparation and pretreatment of the surface. These electrode reactions are slow and occur by a diversity of mechanisms, both chemical and electrochemical steady state electrochemical experiments and electron microscopy were found to be the only satisfactory techniques for their study.
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Published date: 1976
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Local EPrints ID: 458318
URI: http://eprints.soton.ac.uk/id/eprint/458318
PURE UUID: 2e456d1c-74c5-42a4-b4a2-e89a16b42852
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Date deposited: 04 Jul 2022 16:46
Last modified: 04 Jul 2022 16:46
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Author:
Mohammad Amjad Chaudhary
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