SO2 electrooxidation reaction on Pt single crystal surfaces in acidic media: Electrochemical and in situ FTIR studies

Author(s)

Dourado, Andre H. B. ; Del Colle, Vinicius ; Munhos, Renan L. ; Feliu, Juan M. ; Varela, Hamilton ; Cordoba de Torresi, Susana, I

• Document type: Journal article
• Source: Electrochimica Acta; v. 403, p. 12-pg., 2022-01-20.

Abstract

SO2 is a poisonous and anthropogenic gas generated by fossil fuel burning due to the common presence of S-containing contaminants in oil and coal. As a strategy to handle this pollutant and to increase H-2 generation, the electrocatalytic SO2 oxidation reaction (SO2OR) is considered. In this way, SO2 is converted to H2SO4, while hydrogen gas is generated at the cathode. To better understand the mechanism and its dependence on the surface crystallography and electrolyte composition, electrochemical and in situ spectroscopic measurements using Pt single crystal electrodes were performed. The crystallographic orientation of the electrode is shown to be critical not only to the SO2 OR activity but also to the resulting mechanism. The Pt(100) face is found to be the most active electrode in both H2SO4 and HClO4 aqueous electrolytes, and S2O62- appears as a key intermediate for the mechanism. Volcano plots, drawn considering the Stark tuning slope as a quantity proportional to the adsorption energy, show the importance of S2O62- in the electrode catalytic activity. (C) 2021 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 19/22183-6 - Electrocatalysis VI: fundamental and applied aspects of emerging and classical problems in electrochemical energy conversion
• 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)