Electrooxidation of Acetaldehyde on Pt(111) Surface Modified by Random Defects and Tin Decoration
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ORIGINAL RESEARCH
Electrooxidation of Acetaldehyde on Pt(111) Surface Modified by Random Defects and Tin Decoration A. F. B. Barbosa 1,2
&
V. Del Colle 3
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B. A. F. Previdello 1
&
G. Tremiliosi-Filho 1
Accepted: 15 October 2020 # Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Acetaldehyde oxidation was studied on well-ordered Pt(111), stepped Pt(554), and disordered Pt(111). Random superficial defects of the {110}-type were electro-generated on well-ordered Pt(111) surface by successive potential cycling at 0.05 V s−1 between 0.05 and 1.3 V in 0.1 M HClO4 solution. In general, well-ordered Pt(111) is more active than stepped or disordered platinum surfaces for acetaldehyde oxidation. The reaction follows a dual pathways mechanism, leading each pathway to CO2 and acetic acid, respectively, as final products. The CO2 is produced via adsorbed CO and CHx reaction intermediates. Acetic acid comes from the adsorbed acetaldehyde oxidation. Additionally, acetaldehyde was also investigated on well-ordered Pt(111) and disordered Pt(111) surfaces, both modified by deposited tin submonolayers. An outstanding performance was observed when both, well-ordered and disordered Pt(111) surfaces, were modified by Sn. It was observed an extraordinary displacement of the onset potential for more negative potentials and an increased production of CO2 and acetic acid. Keywords Acetaldehyde electrooxidation reaction . Platinum single crystal . Random defects . Tin deposition
Introduction Several reaction pathways are involved in the complete oxidation of ethanol to carbon dioxide which gives rise to various reaction intermediates such as carbon monoxide, acetaldehyde, and acetic acid [1]. Thus, acetaldehyde is an important reaction intermediate involved in the electrooxidation of ethanol and represents an essential species to be considered in the discussion of the alcohol oxidation mechanism. Its interaction with metal electrode surfaces is highly relevant for underElectronic supplementary material The online version of this article (https://doi.org/10.1007/s12678-020-00628-5) contains supplementary material, which is available to authorized users. * G. Tremiliosi-Filho [email protected] 1
Institute of Chemistry of São Carlos, University of São Paulo, Av. Trabalhador São Carlense, 400, São Carlos, SP 13566-590, Brazil
2
Federal Institute of Alagoas-Campus Penedo, Rod. Engenheiro Joaquim Gonçalves, s/n, Penedo, AL 57200-000, Brazil
3
Department of Chemistry, Federal University of Alagoas-Campus Arapiraca, Av. Manoel Severino Barbosa s/n, Arapiraca, AL 57309-005, Brazil
standing one of the reaction characteristics that occur in direct ethanol fuel cells (DEFCs) [2–5]. Additionally, acetaldehyde is the smallest oxygenated molecules that contain a carbon chain [6]. Therefore, its electrooxidation can be considered a model to understand how C–C bonds can be broken in small molecules containing a methyl group [6]. The electrooxidation of acetaldehyde has been the object of several investigations, in
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