Adsorbed Formate is the Last Common Intermediate in the Dual-Path Mechanism of the Electrooxidation of Formic Acid
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Título: | Adsorbed Formate is the Last Common Intermediate in the Dual-Path Mechanism of the Electrooxidation of Formic Acid |
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Autor/es: | Betts, Alexander | Briega-Martos, Valentín | Cuesta, Angel | Herrero, Enrique |
Grupo/s de investigación o GITE: | Electroquímica de Superficies |
Centro, Departamento o Servicio: | Universidad de Alicante. Departamento de Química Física | Universidad de Alicante. Instituto Universitario de Electroquímica |
Palabras clave: | Formic acid | Electrocatalysis | Pt(100) | Pt(111) | Adsorbed formate |
Área/s de conocimiento: | Química Física |
Fecha de publicación: | 22-jun-2020 |
Editor: | American Chemical Society |
Cita bibliográfica: | ACS Catalysis. 2020, 10(15): 8120-8130. https://doi.org/10.1021/acscatal.0c00791 |
Resumen: | We report a study using Pt(111) and Pt(100) electrodes of the role of adsorbed formate in both the direct and indirect pathways of the electrocatalytic oxidation of formic acid. Cyclic voltammetry at different concentrations of formic acid and different scan rates and pulsed voltammetry were used to obtain a deeper insight into the effect of formate coverage on the rate of the direct pathway. Pulsed voltammetry also provided information on the effect of the concentration of formic acid on the rate of the formation of adsorbed CO on Pt(100). At low to medium coverage, increasing formate coverage increases the rate of its direct oxidation, suggesting that decreasing the distance between neighboring bidentate-adsorbed formate favors its interconversion to and/or stabilizes monodentate formate (the reactive species). However, increasing the formate coverage beyond approximately 50% results in a decrease of the rate of the direct oxidation, probably because bidentate formate is too closely packed for its conversion to monodentate formate to be possible. Cyclic voltammetry at very high scan rates reveals the presence of an order–disorder phase transition within the bidentate formate adlayer on Pt(111) when the coverage approaches saturation. The dependence of the potential of the maximum rate of dehydration to adsorbed CO, and of the rate at the maximum, on the concentration of formic acid is in good agreement with predictions made for a mechanism, in which adsorbed CO is formed through the adsorption of formate followed by its reduction to adsorbed CO, thus confirming that monodentate-adsorbed formate is the last intermediate common to both the direct and indirect pathways. |
Patrocinador/es: | This work has been financially supported by the MINECO-FEDER (Spain) through project CTQ2016-76221-P. A.B. and A.C. gratefully acknowledge the support of the University of Aberdeen. |
URI: | http://hdl.handle.net/10045/108723 |
ISSN: | 2155-5435 |
DOI: | 10.1021/acscatal.0c00791 |
Idioma: | eng |
Tipo: | info:eu-repo/semantics/article |
Derechos: | © 2020 American Chemical Society |
Revisión científica: | si |
Versión del editor: | https://doi.org/10.1021/acscatal.0c00791 |
Aparece en las colecciones: | INV - EQSUP - Artículos de Revistas |
Archivos en este ítem:
Archivo | Descripción | Tamaño | Formato | |
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Betts_etal_2020_ACSCatal_final.pdf | Versión final (acceso restringido) | 1,63 MB | Adobe PDF | Abrir Solicitar una copia |
Betts_etal_2020_ACSCatal_accepted.pdf | Accepted Manuscript (acceso abierto) | 819,83 kB | Adobe PDF | Abrir Vista previa |
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