The role of HBF4 in electro-catalysis: Arsenic contamination and anion adsorption

Autor(es)

Santos, Adriano L. ^[1] ; Nagao, Raphael ^[1] ; Oliveira, Cristiane P. ^[1] ; de Lima, Roberto B. ^[2] ; Varela, Hamilton ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

^[2] Univ Fed Maranhao, Dept Chem, BR-65085580 Sao Luis, MA - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 660, n. 1, p. 147-152, SEP 1 2011.
• Citações Web of Science: 5

Resumo

We present in this work a comprehensive investigation of the role played by dissolved tetrafluoroboric acid on the electrochemical response of a polycrystalline platinum electrode in acidic media. HBF(4) from two different suppliers was employed and characterized in terms of the amount of arsenic contamination by Inductively Coupled Plasma-Optical Emission Spectroscopy. The effect of different amounts of HBF(4) on the voltammetric profile of the Pt vertical bar HClO(4)(aq) interface was investigated by means of electrochemical quartz crystal nanobalance (EQCN). Despite the comparable cyclic voltammograms, the presence of arsenic in one of the two HBF(4) used resulted in dramatic variations in the mass change profile, which evidences the deposition/dissolution of arsenic prior to the surface oxidation. For the arsenic-free HBF(4), its effect on the mass change profile was mainly associated to anion adsorption. The impact of dissolved HBF(4) on the electro-oxidation of formic acid was rationalized in terms of two contributions: current enhancement at low potentials due to the arsenic-assisted formic acid electro-oxidation and inhibition at high potentials due to anion adsorption. (C) 2011 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 07/06037-2 - Estudo nanogravimétrico do processo de eletrooxidação superficial do ouro
• Beneficiário: Adriano Lopes Santos
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• 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
• Processo FAPESP: 09/16449-1 - Instabilidades cinéticas em eletrocatálise: mecanismo e dinâmica espaço-temporal
• Beneficiário: Cristiane Pontes de Oliveira
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 09/00153-6 - Auto-organização espaço-temporal em eletrocatálise
• Beneficiário: Raphael Nagao de Sousa
• Modalidade de apoio: Bolsas no Brasil - Doutorado