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Development and evaluation of a pseudoreference Pt / / Ag / AgCl electrode for electrochemical systems / André A. G. F. Beati in Industrial & engineering chemistry research, Vol. 51 N° 14 (Avril 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5367–5371 Titre : Development and evaluation of a pseudoreference Pt / / Ag / AgCl electrode for electrochemical systems Type de document : texte imprimé Auteurs : André A. G. F. Beati, Auteur ; Rafael M. Reis, Auteur ; Robson S. Rocha, Auteur Année de publication : 2012 Article en page(s) : pp. 5367–5371 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrochemical  systems Résumé : The use of standard reference electrodes, such as Ag/AgCl or saturated calomel electrodes, in potentiometric and amperometric studies involving miniaturized electrochemical systems, or those operating under positive hydraulic pressure, is often impractical. Placement of the reference electrode in the direct vicinity of the working electrode is often prohibited by the dimensions or layout of the electrochemical cell, while the alternative strategy of locating the reference electrode in a separate compartment often leads to electrolyte leakage and contamination of the system. In the present study, we have investigated the functionality of a pseudoreference electrode comprising a platinum wire, one end of which was maintained in intimate contact with the internal solution of an Ag/AgCl reference electrode while the other was connected, via a BNC connector, to a platinum probe located within the electrochemical cell. Linear and cyclic voltammetric studies, involving both aqueous and nonaqueous electrolytes, were carried out using the pseudoreference electrode and an electrochemical cup-type cell with three electrodes or an electrochemical flow reactor. In all cases, the functionality of the Pt//Ag/AgCl system was similar to that of a conventional Ag/AgCl reference electrode. Variations in the electrolyte did not alter the potential or voltammetric profile recorded when using the pseudoreference system, although peak currents were generally improved and potential values shifted by approximately +350 mV in comparison with the Ag/AgCl electrode, therefore, the system pseudoreference can be applied in any electrochemical system due to the constant potential difference. It is concluded that the pseudoreference electrode can be used with advantage to obtain potentiometric and amperometric measurements in both simple and complex electrochemical systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2026025 [article] Development and evaluation of a pseudoreference Pt / / Ag / AgCl electrode for electrochemical systems [texte imprimé] / André A. G. F. Beati, Auteur ; Rafael M. Reis, Auteur ; Robson S. Rocha, Auteur . - 2012 . - pp. 5367–5371. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 14 (Avril 2012) . - pp. 5367–5371 Mots-clés : Electrochemical  systems Résumé : The use of standard reference electrodes, such as Ag/AgCl or saturated calomel electrodes, in potentiometric and amperometric studies involving miniaturized electrochemical systems, or those operating under positive hydraulic pressure, is often impractical. Placement of the reference electrode in the direct vicinity of the working electrode is often prohibited by the dimensions or layout of the electrochemical cell, while the alternative strategy of locating the reference electrode in a separate compartment often leads to electrolyte leakage and contamination of the system. In the present study, we have investigated the functionality of a pseudoreference electrode comprising a platinum wire, one end of which was maintained in intimate contact with the internal solution of an Ag/AgCl reference electrode while the other was connected, via a BNC connector, to a platinum probe located within the electrochemical cell. Linear and cyclic voltammetric studies, involving both aqueous and nonaqueous electrolytes, were carried out using the pseudoreference electrode and an electrochemical cup-type cell with three electrodes or an electrochemical flow reactor. In all cases, the functionality of the Pt//Ag/AgCl system was similar to that of a conventional Ag/AgCl reference electrode. Variations in the electrolyte did not alter the potential or voltammetric profile recorded when using the pseudoreference system, although peak currents were generally improved and potential values shifted by approximately +350 mV in comparison with the Ag/AgCl electrode, therefore, the system pseudoreference can be applied in any electrochemical system due to the constant potential difference. It is concluded that the pseudoreference electrode can be used with advantage to obtain potentiometric and amperometric measurements in both simple and complex electrochemical systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2026025

Use of gas diffusion electrode for the in situ generation of hydrogen peroxide in an electrochemical flow - by reactor / Rafael M. Reis in Industrial & engineering chemistry research, Vol. 51 N° 2 (Janvier 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 649-654 Titre : Use of gas diffusion electrode for the in situ generation of hydrogen peroxide in an electrochemical flow - by reactor Type de document : texte imprimé Auteurs : Rafael M. Reis, Auteur ; André A. G. F. Beati, Auteur ; Robson S. Rocha, Auteur Année de publication : 2012 Article en page(s) : pp. 649-654 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Reactor  Hydrogen  production  In  situ  Electrodes  Gaseous  diffusion Résumé : Hydrogen peroxide is a powerful oxidant that finds application in several areas, but most particularly in the treatment of industrial wastewaters. The aim of the present study was to investigate the effects of applied potential and electrolyte flow conditions on the in situ generation of hydrogen peroxide in an electrochemical flow-by reactor with a gas diffusion electrode (GDE). The electrolyses were performed in an aqueous acidic medium using a GDE constructed with conductive black graphite and polytetrafluoroethylene (80:20 w/w). Under laminar flow conditions (flow rate = 50 L/h), hydrogen peroxide was formed in a maximum yield of414mg/L after 2 h at -2.25 Vvs Pt //Ag/AgCl (global rate constant = 3.1 mg/(L min); energy consumption = 22.1 kWh/kg). Under turbulent flow (300 L/h), the maximum yield obtained was 294 mg/L after 2 h at -1.75 V vs Pt//Ag/AgCl (global rate constant = 2.5 mg/(L min); energy consumption =30.1 kWh/kg). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476395 [article] Use of gas diffusion electrode for the in situ generation of hydrogen peroxide in an electrochemical flow - by reactor [texte imprimé] / Rafael M. Reis, Auteur ; André A. G. F. Beati, Auteur ; Robson S. Rocha, Auteur . - 2012 . - pp. 649-654. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 2 (Janvier 2012) . - pp. 649-654 Mots-clés : Reactor  Hydrogen  production  In  situ  Electrodes  Gaseous  diffusion Résumé : Hydrogen peroxide is a powerful oxidant that finds application in several areas, but most particularly in the treatment of industrial wastewaters. The aim of the present study was to investigate the effects of applied potential and electrolyte flow conditions on the in situ generation of hydrogen peroxide in an electrochemical flow-by reactor with a gas diffusion electrode (GDE). The electrolyses were performed in an aqueous acidic medium using a GDE constructed with conductive black graphite and polytetrafluoroethylene (80:20 w/w). Under laminar flow conditions (flow rate = 50 L/h), hydrogen peroxide was formed in a maximum yield of414mg/L after 2 h at -2.25 Vvs Pt //Ag/AgCl (global rate constant = 3.1 mg/(L min); energy consumption = 22.1 kWh/kg). Under turbulent flow (300 L/h), the maximum yield obtained was 294 mg/L after 2 h at -1.75 V vs Pt//Ag/AgCl (global rate constant = 2.5 mg/(L min); energy consumption =30.1 kWh/kg). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476395