The electrocatalytic properties of small amounts of silver (3–17 μg cm−2) electrodeposited on glassy carbon can be sensibly increased by an activation protocol based on pretreatment oxidation/reduction cycles that produces significant changes in particle’s morphology. The catalytic effects on both Oxygen Evolution Reaction (OER) and Oxygen Reduction Reaction (ORR) are evaluated by the onset potentials of the voltammetric curves, and the number of electrons involved in ORR is evaluated by the Levich plot. Tafel plots of both OER and ORR curves obtained after the activation protocol show significant changes that rule out the hypothesis that the catalytic effect could only be attributed to an increased roughness of the samples. Furthermore, the electrochemically active surface area of silver, as measured by the charge involved in Pb underpotential deposition, was found to increase linearly with the amount of depositing silver. On the contrary, the Tafel plots of increasing amounts of silver show that the increase of the catalytic effect with silver loading is not linear as expected in a mere increase of the roughness factor. Levich-Koutecky and Tafel plots evidenced that the highest silver loading showed a catalytic effect greater than that expected on the basis of the electrochemically active surface area.

Electroactivation of Microparticles of Silver on Glassy Carbon for Oxygen Reduction and Oxidation Reactions / M. Innocenti;C. Zafferoni;A. Lavacchi;L. Becucci;F. Di Benedetto;E. Carretti;F. Vizza;M. L. Foresti. - In: JOURNAL OF THE ELECTROCHEMICAL SOCIETY. - ISSN 0013-4651. - STAMPA. - 161:(2014), pp. 3018-3024. [10.1149/2.003407jes]

Electroactivation of Microparticles of Silver on Glassy Carbon for Oxygen Reduction and Oxidation Reactions

INNOCENTI, MASSIMO;ZAFFERONI, CLAUDIO;LAVACCHI, ALESSANDRO;BECUCCI, LUCIA;DI BENEDETTO, FRANCESCO;CARRETTI, EMILIANO;VIZZA, FRANCESCO;FORESTI, MARIA LUISA
2014

Abstract

The electrocatalytic properties of small amounts of silver (3–17 μg cm−2) electrodeposited on glassy carbon can be sensibly increased by an activation protocol based on pretreatment oxidation/reduction cycles that produces significant changes in particle’s morphology. The catalytic effects on both Oxygen Evolution Reaction (OER) and Oxygen Reduction Reaction (ORR) are evaluated by the onset potentials of the voltammetric curves, and the number of electrons involved in ORR is evaluated by the Levich plot. Tafel plots of both OER and ORR curves obtained after the activation protocol show significant changes that rule out the hypothesis that the catalytic effect could only be attributed to an increased roughness of the samples. Furthermore, the electrochemically active surface area of silver, as measured by the charge involved in Pb underpotential deposition, was found to increase linearly with the amount of depositing silver. On the contrary, the Tafel plots of increasing amounts of silver show that the increase of the catalytic effect with silver loading is not linear as expected in a mere increase of the roughness factor. Levich-Koutecky and Tafel plots evidenced that the highest silver loading showed a catalytic effect greater than that expected on the basis of the electrochemically active surface area.
2014
161
3018
3024
M. Innocenti;C. Zafferoni;A. Lavacchi;L. Becucci;F. Di Benedetto;E. Carretti;F. Vizza;M. L. Foresti
File in questo prodotto:
File Dimensione Formato  
Innocenti108.pdf

Accesso chiuso

Tipologia: Versione finale referata (Postprint, Accepted manuscript)
Licenza: DRM non definito
Dimensione 957.61 kB
Formato Adobe PDF
957.61 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/901134
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 23
  • ???jsp.display-item.citation.isi??? 21
social impact