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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Halide adsorption effect on methanol electro-oxidation reaction studied by dynamic instabilities

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Author(s):
Fiori, I. A. [1] ; Melle, G. B. [2, 1] ; Sitta, E. [1]
Total Authors: 3
Affiliation:
[1] Univ Fed Sao Carlos, Chem Dept, Rod Washington Luis, Km 235, BR-235 Sao Carlos, SP - Brazil
[2] Univ Sao Paulo, Chem Inst Sao Carlos, Sao Carlos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 856, JAN 1 2020.
Web of Science Citations: 0
Abstract

The effect of halide anion adsorption on methanol electro-oxidation reaction in acid media was studied by means of thermal effects on both cyclic voltammograms (CV) and oscillations in galvanostatic time series (GTS). While increasing the chloride concentration we observed a monotonically current decrease followed by an increase of apparent activation energy (E-a) in CV, GTS increases the maximum potential (E-max) and decreases both the oscillation frequency (w) and E-a. Poisoning/Freeing rates (dE/dt) increase for a very small Cl- amount but decreases for higher concentrations. Changing Cl- by Br-, albeit observing similar behaviors for currents on CV and w, E-max and E-a changes suggest that Br- probably plays a dual role, i.e. poisoning the surface by its adsorption but also interacting with adsorbed methanol residues. Finally, increasing the pH to 5.6 in a nonadsorbing electrolyte (HClO4/NaF) several oscillations patterns were mapped with a lesser Cl- influence on both CV and GTS. (C) 2019 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
Grantee:Elson Longo da Silva
Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC