Full text
| |
| Author(s): |
Renan Lopes Munhos
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2020-07-22 |
| Examining board members: |
Susana Ines Cordoba de Torresi;
Hamilton Brandão Varela de Albuquerque;
Raphael Nagao de Sousa
|
| Advisor: | Susana Ines Cordoba de Torresi |
| Abstract | |
The world energetic demand grows continuously, which is supplied by fossil fuels, besides CO2, contributes to the pollutants SO2 and NOX. Therefore, the search for cleaner and renewable energy sources, like eolic and photovoltaic, it is fundamental. These sources could be inconstant and produce ahead of the instantaneous demand, requiring new storage forms to subsequent uses: over the generation of solar fuels, like H2, that has a superior energetic density than fossil fuels and produces only water. But, make it from water, demands high thermodynamic potential and it is kinetically limited by oxygen evolution reaction (OER), that could be replaced by SO2 oxidation reaction (SO2OR), mitigating both problems and transforming a pollutant in three important industrial raws: H2, H2SO4 and storing the excedent energy in solar fuel form. The SO2OR has been present a long time ago in literature, but it has some conflicts in what concerns to mechanisms and catalysts. SO2OR was studied on Au and Pt through classical electrochemical techniques and infrared spectroelectrochemistry. For Pt electrode was observed that SO2 adsorbs preferentially on metallic Pt and it is oxidized by PtO and PtOH. The intermediates observed by Infrared were SO3 and S2O62-. To the Au electrode, the electrochemical behavior showed itself totally distinct; it was appearing a bistability region in the j/E profile, and the appearance of galvanostatic and potentiostatic oscillations. It was observed the same intermediates than on Pt plus S2O52- on surface and Au(SO3) in solution, the last species is a characteristic product of electrode corrosion. The manifestation of all these species is influenced by chaotropicity of the system, which selects the adsorption conformations of SO2 and the water interfacial structure. (AU) | |
| 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 |