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Dynamic electro-chemo-mechanical analysis at the metal-electrolyte interface
Citation Link: https://doi.org/10.15480/882.1169
Publikationstyp
Doctoral Thesis
Date Issued
2014
Sprache
English
Author(s)
Advisor
Title Granting Institution
Technische Universität Hamburg
Place of Title Granting Institution
Hamburg
Examination Date
2014-04-14
TORE-DOI
The link between the mechanical deformation and the electrochemical processes on the surfaces of metal electrodes is experimentally studied.
Firstly, Dynamic Electro-Chemo-Mechanical Analysis (DECMA) is designed and validated as a precise experimental strategy to investigate the potential- and current- modulation in response to the cyclic elastic strain during the cyclic voltammetry. Secondly, the mechanically modulated catalysis is investigated experimentally by monitoring the reaction current modulation during the strain cycles on the electrode. As a model process in study, the hydrogen evolution reaction (HER) is focused in experiments on 111-textured, polycrystalline gold and platinum thin film electrodes. The results show the strain-dependence of the hydrogen adsorption enthalpy as well as the reaction activation enthalpy in HER.
The main conclusion is that the reaction rate of heterogeneous catalysis varies considerably when the surface is elastically strained in the tangent plane. This opens a new perspective on tuning the elastic deformation - in other words, tuning the lattice parameter of surface atoms - of catalysts, so as to enhance their reactivity. The approach of monitoring mechanically modulated reaction rates in electrocatalysis can be also applied to the electrocatalytic reactions of interest. It is prospected as a tool for studying strain-dependent catalysis and for investigating reaction mechanism.
Firstly, Dynamic Electro-Chemo-Mechanical Analysis (DECMA) is designed and validated as a precise experimental strategy to investigate the potential- and current- modulation in response to the cyclic elastic strain during the cyclic voltammetry. Secondly, the mechanically modulated catalysis is investigated experimentally by monitoring the reaction current modulation during the strain cycles on the electrode. As a model process in study, the hydrogen evolution reaction (HER) is focused in experiments on 111-textured, polycrystalline gold and platinum thin film electrodes. The results show the strain-dependence of the hydrogen adsorption enthalpy as well as the reaction activation enthalpy in HER.
The main conclusion is that the reaction rate of heterogeneous catalysis varies considerably when the surface is elastically strained in the tangent plane. This opens a new perspective on tuning the elastic deformation - in other words, tuning the lattice parameter of surface atoms - of catalysts, so as to enhance their reactivity. The approach of monitoring mechanically modulated reaction rates in electrocatalysis can be also applied to the electrocatalytic reactions of interest. It is prospected as a tool for studying strain-dependent catalysis and for investigating reaction mechanism.
Subjects
strain-effects in electrocatalysis
electrocapillarity
electrochemistry
DDC Class
620: Ingenieurwissenschaften
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