Abstract
This research used molecular modeling and rotating disk electrode experiments (RDE) to investigate possible reaction pathways for persulfate production via electrolysis of sulfuric acid solutions using boron doped diamond (BDD) film anodes. Density functional theory (DFT) modeling indicated that uncatalyzed oxidation of SO42- and HSO4-occurs at lower potentials than water oxidation, and that sulfate radical species (SO4-• and HSO4•) may be produced via direct electron transfer, or via reaction with hydroxyl radicals. The RDE experiments indicated that rates of persulfate generation were strongly dependent of the condition of the electrode surface, and that aged electrode surfaces favored water oxidation over direct SO42 and HSO4- oxidation. Combination of sulfate radical species in solution is the lowest energy pathway for persulfate production. Sulfate radical species may also react with radical sites on the electrode surface and produce chemisorbed intermediates that can stabilize sulfate radical species. Reaction of the chemisorbed intermediates with a bisulfate radical can produce persulfate via a surface catalyzed pathway. However, the activation barriers for this pathway are much higher than those for persulfate production via solution phase species.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 68-74 |
| Number of pages | 7 |
| Journal | Electrochimica Acta |
| Volume | 150 |
| DOIs | |
| State | Published - Dec 20 2014 |
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Keywords
- Anode
- BDD
- Boron doped diamond
- Electrosynthesis
- Persulfate
ASJC Scopus subject areas
- Electrochemistry
- Chemical Engineering(all)
Cite this
Understanding persulfate production at boron doped diamond film anodes. / Davis, Jake; Baygents, James C; Farrell, James.
In: Electrochimica Acta, Vol. 150, 20.12.2014, p. 68-74.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Understanding persulfate production at boron doped diamond film anodes
AU - Davis, Jake
AU - Baygents, James C
AU - Farrell, James
PY - 2014/12/20
Y1 - 2014/12/20
N2 - This research used molecular modeling and rotating disk electrode experiments (RDE) to investigate possible reaction pathways for persulfate production via electrolysis of sulfuric acid solutions using boron doped diamond (BDD) film anodes. Density functional theory (DFT) modeling indicated that uncatalyzed oxidation of SO42- and HSO4-occurs at lower potentials than water oxidation, and that sulfate radical species (SO4-• and HSO4•) may be produced via direct electron transfer, or via reaction with hydroxyl radicals. The RDE experiments indicated that rates of persulfate generation were strongly dependent of the condition of the electrode surface, and that aged electrode surfaces favored water oxidation over direct SO42 and HSO4- oxidation. Combination of sulfate radical species in solution is the lowest energy pathway for persulfate production. Sulfate radical species may also react with radical sites on the electrode surface and produce chemisorbed intermediates that can stabilize sulfate radical species. Reaction of the chemisorbed intermediates with a bisulfate radical can produce persulfate via a surface catalyzed pathway. However, the activation barriers for this pathway are much higher than those for persulfate production via solution phase species.
AB - This research used molecular modeling and rotating disk electrode experiments (RDE) to investigate possible reaction pathways for persulfate production via electrolysis of sulfuric acid solutions using boron doped diamond (BDD) film anodes. Density functional theory (DFT) modeling indicated that uncatalyzed oxidation of SO42- and HSO4-occurs at lower potentials than water oxidation, and that sulfate radical species (SO4-• and HSO4•) may be produced via direct electron transfer, or via reaction with hydroxyl radicals. The RDE experiments indicated that rates of persulfate generation were strongly dependent of the condition of the electrode surface, and that aged electrode surfaces favored water oxidation over direct SO42 and HSO4- oxidation. Combination of sulfate radical species in solution is the lowest energy pathway for persulfate production. Sulfate radical species may also react with radical sites on the electrode surface and produce chemisorbed intermediates that can stabilize sulfate radical species. Reaction of the chemisorbed intermediates with a bisulfate radical can produce persulfate via a surface catalyzed pathway. However, the activation barriers for this pathway are much higher than those for persulfate production via solution phase species.
KW - Anode
KW - BDD
KW - Boron doped diamond
KW - Electrosynthesis
KW - Persulfate
UR - http://www.scopus.com/inward/record.url?scp=84909584443&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84909584443&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2014.10.104
DO - 10.1016/j.electacta.2014.10.104
M3 - Article
AN - SCOPUS:84909584443
VL - 150
SP - 68
EP - 74
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
ER -