The significance of non-covalent interactions on the electro-oxidation of alcohols on Pt and Au in alkaline media

Autor(es)

Angelucci, Camilo Andrea ^[1] ; Varela, Hamilton ^[2] ; Tremiliosi-Filho, Germano ^[2] ; Gomes, Janaina Fernandes ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210170 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Electrochemistry Communications; v. 33, p. 10-13, AUG 2013.
• Citações Web of Science: 31

Resumo

The importance of the cation effect on the electro-oxidation of glycerol and ethylene glycol on Pt and Au in alkaline media was investigated by cyclic voltammetry and chronoamperometry. The reaction on Pt is influenced by OHad-M+(H2O)(x) clusters from non-covalent interactions between hydrated alkali metal cations (M+(H2O)(x), M+ = Li+, Na+ and K+) and OHad on Pt, as previously reported for many electro-catalytic reactions on Pt. Contrarily, the impact of OHad-M+(H2O)(x) clusters on the electro-oxidation of these alcohols over Au is not significant. Different behaviors of Pt and Au in alkaline solutions are not associated with distinct surface coverage degrees of oxygenated species formed on Pt and Au at the glycerol and ethylene glycol oxidation region, but rather with the potential region at which the electro-oxidation of these alcohols takes place on Pt and Au. The reactions occur at lower potentials on Pt than on Au. At high potentials, electrostatic repulsion between the positively charged Au surface and cations is mandatory for weakening non-covalent interactions between hydrated alkali metal cations and surface oxygenated species. (c) 2013 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 09/07629-6 - Eletrocatálise IV: aspectos fundamentais e aplicados dos processos eletrocatalíticos, bio-eletrocatálise e instabilidades cinéticas
• Beneficiário: Edson Antonio Ticianelli
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Temático