Electrochemical oxidation of dissolved sulphur dioxide at platinum and gold electrodes

Seo, Eddie T.; Sawyer, Donald T.

doi:10.1016/0013-4686(65)87022-0

Cited by 94 publications

(64 citation statements)

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“…First of all, according to Garsany et al [13], the adsorbed SO 2 are wholly on the surface of Pt, and the Vulcan carbon does not adsorb SO 2 . Moreover, we already know the relativity between potential and the oxidation state of sulfur [19,[21][22][23][24][25][26]. At the potential of 0.65 V, an unchanged product of SO 2 adsorption was formed on Pt surfaces.…”

Section: Resultsmentioning

confidence: 99%

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

Xie

Shao

Zhang

et al. 2012

Electrochimica Acta

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a b s t r a c tA quantitative research on S and SO 2 poisoning Pt/Vulcan carbon (Pt/VC) catalysts for fuel cells was conducted by the three-electrode method. Pt/VC electrodes were contaminated by submersion in a SO 2 -containing solution made up of 0.2 mM Na 2 SO 3 and 0.5 M H 2 SO 4 for different periods of time, and held at 0.05 V (vs. RHE) in 0.5 M H 2 SO 4 solutions in order to gain zero-valence sulfur (S 0 ) poisoned electrodes. The sulfur coverage of Pt was determined from the total charge consumed as the sulfur was oxidized from S 0 at 0.05 V (vs. RHE) to sulfate at >1.1 V (vs. RHE). The summation of initial coverage of S 0 (Â S ) and coverage of H (Â H ) are approximately equal to 1 (Â H + Â S = 1) when 0.5 < Â H < 1, which gives an easy way to figure out the quantity of sulfur adsorbed on Pt/VC. As to SO 2 poisoned Pt/VC, the catalytic activity of oxygen reduction reaction (ORR) decreases linearly with the amount of SO 2 adsorbed on the Pt nanoparticles when 0.45 < Â H < 0.81. When the adsorbed SO 2 was reduced to S 0 , the mass activity was greatly recovered, and the area specific activity was even higher than the unpoisoned Pt/VC.

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Section: Resultsmentioning

confidence: 99%

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

Xie

Shao

Zhang

et al. 2012

Electrochimica Acta

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“…The less positive peak does correspond to a diffusion-limited, two-electron oxidation of SO 2 , which takes place through a weakly adsorbed species as an intermediate. The more positive peak however was associated with a surface process: the oxidative desorption of strongly adsorbed SO 2 . Recent Surface Enhanced Raman Scattering (SERS) studies of roughened gold in contact with aqueous SO 2 [5] revealed a band at 1130 cm − 1 , which was ascribed to adsorbed SO 2 .…”

Section: Introductionmentioning

confidence: 97%

“…Seo and Sawyer [2] distinguished two modes for the electrochemical oxidation of SO 2 on gold. The first was ascribed to a purely electrochemical charge-transfer process and the second to a chemical oxidation by electrochemically generated metal oxide.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical behaviour of aqueous SO2 at polycrystalline gold electrodes in acidic media. A voltammetric and in-situ vibrational study. Part II. Oxidation of SO2 on bare and sulphur-modified electrodes

Quijada

Morallón

Vázquez

et al. 2001

Electrochimica Acta

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The electrochemical oxidation of SO 2 on polycrystalline gold electrodes has been studied by means of cyclic voltammetry and in situ vibrational techniques. On bare gold electrodes, SO 2 is irreversibly oxidised on forward scans at 0.6 V/RHE, featuring a diffusion-limited peak. Oxidation is inhibited by the formation of chemisorbed oxygen. A SO 2 anodic current rise occurs on the reverse scan in parallel with the reduction of the metal oxide layers. As shown by FT-IR, oxidation proceeds to yield a mixture of soluble S(VI) species as stable reaction products. From vibrational spectra and results from the irreversible adsorption method, it follows that no strongly adsorbed S -O-like residues are present onto the gold surface in the region 0.3-0.5 V/RHE. On sulphur-modified electrodes improved electrocatalysis is manifested by the shift of the diffusion-limited peak to lower potentials. The best performance is observed at a sulphur coverage of 0.5. At higher coverage, sulphur adlayers impart lower catalytic efficiency and eventually show strong poisoning properties. This behaviour is exhibited by sulphur adlayers generated either in situ by SO 2 reduction or ex situ by sulphide adsorption/oxidation in acidic or alkaline media.

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“…9 The mechanism of SO 2 oxidation in water is complex, the absorption of sulfur dioxide into aqueous solution is followed by several possible equilibrium processes. [10][11][12][13] SO 2 (g) → SO 2 (aqu)At pH < 2, the mechanism leading to sulfate formation is suggested.There are many factors affecting the reaction process, the effect of pH and activation of SO 3 2-ion has been discussed.14 Absorption and oxidation of SO 2 has typically necessitated the use of Separate operations, and an electrolytic cell is used to restore absorption liquid performance. The using of electrodialysis in purification is potentially an attractive alternative to the promotion of absorption and enrichment.…”

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Remove Sulfur Dioxide from Flue Gases to Obtain Sulfuric Acid through Electrodialysis Enrichment

NingPing

et al. 2015

J. Electrochem. Soc.

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This article illustrates the experimental research which disposes low concentration SO 2 flue gases through liquid absorption and electrodialysis enrichment. It introduces the technology and devices to produce sulfuric acid by liquid absorption and oxidation of low concentration SO 2 in aqueous solutions as well as electrodialysis enrichment in the same reactor. Numerous experiments have been carried out in order to observe the performance of the reactor under the operating conditions: the current density, temperature, volume flow rate of the electrolyte, the sulfuric acid concentration, volume flow rate of the gas, the components of gas mixture, and initial SO 2 concentration. When the removal rate of SO 2 reaches 83.64%, we eventually get sulfuric acid with the concentration of 28.56%. Sulfur dioxide in flue gas generated from the combustion of fossil fuel, such as metal smelting factory, thermal power plants, etc. It is the main cause of air pollution and acid rain. Many countries have therefore adopted strict regulations to SO 2 emissions from coal and oil-fired boilers, which are one of the primary sources of SO 2 emissions. The increasing importance of sulfur dioxide pollution control stimulated the improvement of technology for the removal of sulfur dioxide from flue and waste gases.The electrochemical processes which do not require the continuous use of chemical reagents, possess advantages and bring a helpful contribution in the proposal or development of depollution processes. 1 Sulfur dioxide can be oxidized electrochemically to species such as sulfuric acid and dithionite, the electrochemical oxidation of SO 2 has been investigated both as a pollution control method and as part of recycling and utilization of resources.2,3 The electrochemical oxidation of sulfur dioxide can be achieved either through a direct process at an anode surface or using a redox mediator through a chemical process, which has to be regenerated at the electrode. 4 In the electrolysis of the sulfur dioxide absorbed in aqueous solution, the process involves a chemical oxidation of SO 2 by adsorbed oxygen species.5 It is also possible that SO 2 is oxidized at the anode while hydrogen is produced at the cathode.6 Furthermore, the removal of SO 2 from the copper ions containing wastes provides electrowinning of copper simultaneously. 7The main products of electrochemical oxidation and reduction of SO 2 in acid solution are sulfuric acid and sulfur, respectively. The formation of sulfur may come with a significant solids handling problem and can lead to problems in cell operation.8 In many applications, for example, in the chemical process industries, sulfuric acid is a desirable product as it can be used in chemical manufacture and is readily transported.The overall reaction for the oxidation of SO 2 can be written as:Where hydrogen is formed at the cathode. Dissolved sulfur dioxide is converted to sulfuric acid at the anode and hydrogen is formed at the cathode. 9 The mechanism of SO 2 oxidation in water is complex, the absorption ...

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Electrochemical oxidation of dissolved sulphur dioxide at platinum and gold electrodes

Cited by 94 publications

References 9 publications

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

A quantitative research on S- and SO2-poisoning Pt/Vulcan carbon fuel cell catalyst

Electrochemical behaviour of aqueous SO2 at polycrystalline gold electrodes in acidic media. A voltammetric and in-situ vibrational study. Part II. Oxidation of SO2 on bare and sulphur-modified electrodes

Remove Sulfur Dioxide from Flue Gases to Obtain Sulfuric Acid through Electrodialysis Enrichment

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