کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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60181 | 1419464 | 2012 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Polysulfide Poisoning of Ag Electrocatalyst during L-Ascorbate Ion Electro-oxidation in Alkaline Solution Polysulfide Poisoning of Ag Electrocatalyst during L-Ascorbate Ion Electro-oxidation in Alkaline Solution](/preview/png/60181.png)
L-ascorbate anion electro-oxidation on a silver electrode in hydroxide solution in the absence and presence of sodium polysulfide of concentrations from 1 × 10−5 to 4.5 × 10−4 mol/L was studied using cyclic voltammetry and electrochemical impedance spectroscopy. Both hydroxide and polysulfide ions inhibited L-ascorbate ion oxidation, with the poisoning effect of polysulfide ion being more pronounced in the potential range of −0.3 to −0.2 V/SCE. The time constants for L-ascorbate ion oxidation in the absence and presence of polysulfide were, 10−3 to 1 × 10−2 s and 1 × 10−4 to 1 × 10−2 s, respectively depending on the potential used for the impedance analysis. Based on the cyclic voltammetry findings, a mechanism for L-ascorbate oxidation in the presence of polysulfide ions was proposed. Impedance calculations based on the kinetic analysis can account for the occurrence of a negative impedance in a potential region around −0.2 V/SCE in the Nyquist polts.
The electro-catalytic oxidation of L-ascorbate ion on a Ag electrode in the presence of adsorbed hydroxide and poly sulfide anions was investigated using electrochemical methods. Both hydroxide and polysulfide ions inhibited L-ascorbate ion oxidation, with the poisoning effect of polysulfide ion being more pronounced in the potential range of −0.3 to −0.2 V/SCE.Figure optionsDownload as PowerPoint slide
Journal: Chinese Journal of Catalysis - Volume 33, Issues 2–3, February–March 2012, Pages 267–274