Reactions of some transition metal compounds in alkali metal sulphate melts
Reactions of some transition metal compounds in alkali metal sulphate melts
The ternary eutectic melt, composed of lithium sulphate, sodium sulphate and potassium sulphate, was the principal solvent used. Subjects studied included reactions of vanadium compounds in sulphur dioxide/sulphur trioxide/air/nitrogen atmospheres; the influence of transition metal compounds on the contact catalyst, and Lux-Flood acid-base properties and electronic spectra of their melt solutions; and the behaviour of some sulphur-containing anions. Vanadium(V), chromium(VI), and possibly molybdenum(VI) and tungsten(VI) compounds underwent acid-base reactions with potassium pyrosulphate and sodium carbonate. An acidic vanadium(V) species was possibly stabilised by complex formation with excess sulphate. First row transition metal sulphates were soluble and reacted with sodium carbonate, forming insoluble oxides soluble on addition of pyrosulphate.In sulphur dioxide-containing atmospheres, chromate(VI) solutions were reduced to chromium(III), and iron(III) to iron(II), but molybdenum(VI) was not reduced. Under sulphur dioxide/air, vanadium pentoxide solutions were partially reduced to vanadium(IV), and possibly vanadium(V) was dimeric and vanadium(IV) monomeric.Molybdenum trioxide increased slightly the efficiency of the vanadium contact catalyst for oxidising sulphur dioxide, while several first row transition metal compounds were deleterious. Sodium sulphite disproportionated to sulphide and sulphate, and reacted with pyrosulphate, evolving sulphur dioxide and sulphur.
University of Southampton
1978
Dearnaley, Roger Irvine
(1978)
Reactions of some transition metal compounds in alkali metal sulphate melts.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The ternary eutectic melt, composed of lithium sulphate, sodium sulphate and potassium sulphate, was the principal solvent used. Subjects studied included reactions of vanadium compounds in sulphur dioxide/sulphur trioxide/air/nitrogen atmospheres; the influence of transition metal compounds on the contact catalyst, and Lux-Flood acid-base properties and electronic spectra of their melt solutions; and the behaviour of some sulphur-containing anions. Vanadium(V), chromium(VI), and possibly molybdenum(VI) and tungsten(VI) compounds underwent acid-base reactions with potassium pyrosulphate and sodium carbonate. An acidic vanadium(V) species was possibly stabilised by complex formation with excess sulphate. First row transition metal sulphates were soluble and reacted with sodium carbonate, forming insoluble oxides soluble on addition of pyrosulphate.In sulphur dioxide-containing atmospheres, chromate(VI) solutions were reduced to chromium(III), and iron(III) to iron(II), but molybdenum(VI) was not reduced. Under sulphur dioxide/air, vanadium pentoxide solutions were partially reduced to vanadium(IV), and possibly vanadium(V) was dimeric and vanadium(IV) monomeric.Molybdenum trioxide increased slightly the efficiency of the vanadium contact catalyst for oxidising sulphur dioxide, while several first row transition metal compounds were deleterious. Sodium sulphite disproportionated to sulphide and sulphate, and reacted with pyrosulphate, evolving sulphur dioxide and sulphur.
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Published date: 1978
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Local EPrints ID: 458394
URI: http://eprints.soton.ac.uk/id/eprint/458394
PURE UUID: 7fbae975-54ec-4052-82ee-e1b40328ec41
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Date deposited: 04 Jul 2022 16:48
Last modified: 04 Jul 2022 16:48
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Author:
Roger Irvine Dearnaley
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