Electrochemical kinetics of molten potassium thiocyanate on platinum : Mechanisms of anodic film formation and its cathodic dissolution

The kinetics and mechanism of the anodic film formation and its cathodic dissolution on platinum, through electrolysis of molten potassium thiocyanate, were studied. Experiments were made at 190°C by applying both repetitive and single pulse linear sweep voltammetry. The kinetics of the anodic film...

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Autores principales: Arvia, Alejandro Jorge, Calandra, Alfredo J., Martins, María Elisa
Formato: Articulo
Lenguaje:Inglés
Publicado: 1972
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Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/119486
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id I19-R120-10915-119486
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Exactas
Química
Anodic film formation
Cathodic dissolution
Molten potassium thiocyanate
spellingShingle Ciencias Exactas
Química
Anodic film formation
Cathodic dissolution
Molten potassium thiocyanate
Arvia, Alejandro Jorge
Calandra, Alfredo J.
Martins, María Elisa
Electrochemical kinetics of molten potassium thiocyanate on platinum : Mechanisms of anodic film formation and its cathodic dissolution
topic_facet Ciencias Exactas
Química
Anodic film formation
Cathodic dissolution
Molten potassium thiocyanate
description The kinetics and mechanism of the anodic film formation and its cathodic dissolution on platinum, through electrolysis of molten potassium thiocyanate, were studied. Experiments were made at 190°C by applying both repetitive and single pulse linear sweep voltammetry. The kinetics of the anodic film formation is a film-growth-rate controlled process, whose mechanism comprises various steps: discharge, nucleus formation and growth. The discharge step is a fast process and the second step is postulated as rate-determining at low potential sweep rates; the corresponding Tafel slope is RT/2F. At higher potentials the larger reaction rates achieved make reaction sites undistinguishable. This fact reflects a change of reaction mechanism involving a different Tafel slope for the anodic film formation, which is twice the former slope. The corresponding E/I curves are theoretically evaluated with parameters derived from the postulated mechanisms. The dissolution process is not definitely established although the likely pathway is envisaged. The catholic reaction is characterized by a Tafel slope of RT/F. The dissolution comprises a fast electron-transfer step followed by thiocyanate-ion formation; the latter appears as the slowest step.
format Articulo
Articulo
author Arvia, Alejandro Jorge
Calandra, Alfredo J.
Martins, María Elisa
author_facet Arvia, Alejandro Jorge
Calandra, Alfredo J.
Martins, María Elisa
author_sort Arvia, Alejandro Jorge
title Electrochemical kinetics of molten potassium thiocyanate on platinum : Mechanisms of anodic film formation and its cathodic dissolution
title_short Electrochemical kinetics of molten potassium thiocyanate on platinum : Mechanisms of anodic film formation and its cathodic dissolution
title_full Electrochemical kinetics of molten potassium thiocyanate on platinum : Mechanisms of anodic film formation and its cathodic dissolution
title_fullStr Electrochemical kinetics of molten potassium thiocyanate on platinum : Mechanisms of anodic film formation and its cathodic dissolution
title_full_unstemmed Electrochemical kinetics of molten potassium thiocyanate on platinum : Mechanisms of anodic film formation and its cathodic dissolution
title_sort electrochemical kinetics of molten potassium thiocyanate on platinum : mechanisms of anodic film formation and its cathodic dissolution
publishDate 1972
url http://sedici.unlp.edu.ar/handle/10915/119486
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AT calandraalfredoj electrochemicalkineticsofmoltenpotassiumthiocyanateonplatinummechanismsofanodicfilmformationanditscathodicdissolution
AT martinsmariaelisa electrochemicalkineticsofmoltenpotassiumthiocyanateonplatinummechanismsofanodicfilmformationanditscathodicdissolution
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