Influence of the Electrode and Chaotropicity of the Electrolyte on the Oscillatory Behavior of the Electrocatalytic Oxidation of SO2

Author(s)

Dourado, Andre H. B. ^[1] ; Munhos, Renan L. ^[1] ; Varela, Hamilton ^[2] ; Cordoba de Torresi, Susana I. ^[1] ; Arenz, Matthias ^{[3, 4]}

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Av Prof Lineu Prestes, BR-05508080 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Inst Quim Sao Carlos, CP 780, BR-13560970 Sao Carlos, SP - Brazil

^[3] Kobenhavn Univ, Chem Dept, Univ Pk 5, DK-2100 Copenhagen - Denmark

^[4] Univ Bern, Dept Chem & Biochem, Freiestr 3, CH-3012 Bern - Switzerland

• Document type: Journal article
• Source: Journal of Physical Chemistry C; v. 122, n. 2, p. 1243-1247, JAN 18 2018.
• Web of Science Citations: 3

Abstract

SO2 oxidation has been proposed as an alternative pathway for the electrochemical generation of H-2 because it requires lower potentials than water splitting and at the same time consumes an atmospheric pollutant. Theoretical predictions suggest that gold and platinum are the most active catalysts for this reaction. This work presents experimental evidence that, contrary to the predictions, SO2 oxidation starts at less positive potentials on Au electrodes (ca. 0.60 V (vs RHE)) than on Pt. It is found further that the observed current densities on Au are one order of magnitude higher than on Pt. In addition, the SO2 oxidation mechanism depends on the chemical nature of the electrolyte used: A kosmotropic anion (HSO4) results in lower currents than a chaotropic one (ClO4-), and the latter displays oscillatory reaction rates under both potentiostatic and galvanostatic regimes. (AU)

• FAPESP's process: 13/16930-7 - Electrocatalysis V: electrocatalytic processes of chemical and electrical energy interconversion
• Grantee: Edson Antonio Ticianelli
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/26308-7 - Optimization of the physicochemical properties of nano -structured materials for applications in molecular recognition, catalysis and energy conversion/storage
• Grantee: Roberto Manuel Torresi
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/09346-8 - Electrochemical oxidation of Sulfur dioxide onto nanostrutured gold catalysts
• Grantee: Renan Lopes Munhos
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 13/25592-8 - Study of L-cysteine and L-cystine adsorption on platinum electrodes
• Grantee: André Henrique Baraldi Dourado
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• FAPESP's process: 15/08300-9 - Study of L-cysteine and L-cystine adsorption and oxidation on Pt electrode by internal reflection infrared spectroscopy and DEMS
• Grantee: André Henrique Baraldi Dourado
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)