Long-Lasting Oscillations in the Electro-Oxidation of Formic Acid on PtSn Intermetallic Surfaces

Autor(es)

Perini, Nickson ^[1] ; Batista, Bruno C. ^[1] ; Angelo, Antonio C. D. ^[2] ; Epstein, Irving R. ^{[3, 4]} ; Varela, Hamilton ^{[1, 5]}

Afiliação do(s) autor(es)

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

^[2] UNESP, Electrocatalysis Lab, BR-17033360 Bauru, SP - Brazil

^[3] Brandeis Univ, Dept Chem, Waltham, MA 02454 - USA

^[4] Brandeis Univ, Volen Ctr Complex Syst, Waltham, MA 02454 - USA

^[5] Max Planck Gesell, Fritz Haber Inst, Dept Phys Chem, D-14195 Berlin - Germany

• Tipo de documento: Artigo Científico
• Fonte: ChemPhysChem; v. 15, n. 9, p. 1753-1760, JUN 23 2014.
• Citações Web of Science: 15

Resumo

Even when in contact with virtually infinite reservoirs, natural and manmade oscillators typically drift in phase space on a time-scale considerably slower than that of the intrinsic oscillator. A ubiquitous example is the inexorable aging process experienced by all living systems. Typical electrocatalytic reactions under oscillatory conditions oscillate for only a few dozen stable cycles due to slow surface poisoning that ultimately results in destruction of the limit cycle. We report the observation of unprecedented long-lasting temporal oscillations in the electro-oxidation of formic acid on an ordered intermetallic PtSn phase. The introduction of Sn substantially increases the catalytic activity and retards the irreversible surface oxidation, which results in the stabilization of more than 2200 oscillatory cycles in about 40 h; a 30-40-fold stabilization with respect to the behavior of pure Pt surfaces. The dynamics were modeled and numerical simulations point to the surface processes underlying the high stability. (AU)

• Processo FAPESP: 12/24152-1 - Cinética complexa em sistemas eletroquímicos: mecanismos, análise de redes estequiométricas e simulações numéricas
• Beneficiário: Hamilton Brandão Varela de Albuquerque
• Modalidade de apoio: Bolsas no Exterior - Pesquisa
• 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