Effect of preadsorbed sulfur on the electrochemical reduction of nitric oxide
The effect of adsorbed sulfur on platinum black/Teflon gas diffusion electrodes has been studied. The controlled deposition and characterization of intermediate coverages of sulfur (fractional sulfur coverages, {Theta}, between 0 and 1.0, based on the total number of Pt surface sites) was first studied, followed by an investigation of the effects of this preadsorbed sulfur on the electrogenerative (i.e. galvanic) reduction of pure and dilute (3%) NO feeds. These effects are discussed in terms of possible applications for electrogenerative NO reduction, especially hydroxylamine production and flue gas scrubbing applications. Sulfur was deposited through electrochemical reduction of sulfur dioxide which had bene previously adsorbed from SO{sub 2}-containing aqueous sulfuric acid solutions. The sulfur layers deposited in this manner were electrochemically characterized using linear sweep and cyclic voltammetry. Sulfur/hydrogen coadsorption coverage plots constructed from coulometric measurements were studied and yielded evidence that a sulfur bilayer is formed on the electrode. In the presence of adsorbed sulfur (0.2 < {Theta} < 1.0) the current generated by the nitric oxide-hydrogen electrogenerative cell was diminished. This effect was more pronounced with pure NO feeds. The decreased cell current involved not only diminished NO conversion, but also a change in product distribution brought about by adsorbed sulfur. At low sulfur coverages and low cell potentials ammonia is the predominant product, but at higher sulfur coverages selectivity shifts to favor hydroxylamine production. Nitrous oxide is formed only at high cell potentials at all sulfur coverages, and nitrogen formation is allowed at lower sulfur coverages but inhibited at higher coverages.
- Research Organization:
- Wisconsin Univ., Madison, WI (USA)
- OSTI ID:
- 5500353
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NITRIC OXIDE
REDUCTION
SULFUR
DEPOSITION
ADSORPTION
AMMONIA
CORRELATIONS
DENITRIFICATION
DEPOSITS
ELECTROCHEMICAL CELLS
ELECTRODES
FLUE GAS
HYDROGEN
HYDROXYLAMINE
LAYERS
MORPHOLOGY
NITROGEN
NITROUS OXIDE
PLATINUM
SULFUR DIOXIDE
SURFACE PROPERTIES
SYNTHESIS
VOLTAMETRY
AMINES
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
GASEOUS WASTES
HYDRIDES
HYDROGEN COMPOUNDS
METALS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN OXIDES
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
SORPTION
SULFUR COMPOUNDS
SULFUR OXIDES
TRANSITION ELEMENTS
WASTES
010800* - Coal
Lignite
& Peat- Waste Management