Analysis of the hydrogen electrode reaction mechanism in thin-layer cells. 3. Study of hydrogen electro-oxidation by scanning electrochemical microscopy

Authors
Brites Helú, Mariela Alicia; Fernandez, Jose Luis
Publication Year
2017
Language
English
Format
article
Status
Published version
Description
Scanning electrochemical microscopy (SECM) in the feedback mode was used to analyze the complete mechanism of the hydrogen oxidation reaction (hor). A general SECM equation was proposed to carry out the kinetic analysis of the dependences of the tip current (iT) on the substrate potential (ES) and on the tip-substrate distance (d). This SECM equation involves the contribution of a thin-layer cell (TLC) with no aprioristic restrictions about the reaction mechanism. A dependence of the TLC current on ES previously developed for the hor operating through the Tafel-Heyrovsky-Volmer mechanism was included in the proposed SECM model. The domain of conditions where the equation properly reproduces the SECM responses was determined by contrasting the calculated iT(ES, d) dependences with simulated curves obtained by a numerical method using varied kinetic and geometric parameters. The experimental conditions where the model can be used were explored by analyzing the hor on Pt. The present treatment provides a versatile tool for the application of SECM to the kinetic and mechanistic analysis of the hor, which can be easily adapted for the analysis of any multi-step electrocatalyzed reaction on infinite substrates.
Fil: Brites Helú, Mariela Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Programa de Electroquímica Aplicada e Ingeniería Electroquímica; Argentina
Fil: Fernandez, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Programa de Electroquímica Aplicada e Ingeniería Electroquímica; Argentina
Subject
HYDROGEN OXIDATION REACTION
KINETIC ANALYSIS
REACTION MECHANISM
SCANNING ELECTROCHEMICAL MICROSCOPY
THIN-LAYER CELL
Otras Ciencias Químicas
Ciencias Químicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/66012