Oscillatory instabilities in the electrooxidation of borohydride on platinum

Autor(es)

Machado, Eduardo G. ^[1] ; Varela, Hamilton ^[1]

Afiliação do(s) autor(es)

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

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 25, n. 3, p. 442-447, MAR 2014.
• Citações Web of Science: 1

Resumo

The borohydride ion has been pointed as a promising alternative fuel. Most of the investigation on its electrochemistry is devoted to the electrocatalytic aspects of its electrooxidation on platinum and gold surfaces. Besides the known kinetic limitations and intricate mechanism, our Group has recently found the occurrence of two regions of bi-stability and autocatalysis in the electrode potential during the open circuit interaction of borohydride and oxidized platinum surfaces. Following this previous contribution, the occurrence of more complicated phenomena is here presented: namely the presence of electrochemical oscillations during the electrooxidation of borohydride on platinum in alkaline media. Current oscillations were found to be associated to two distinct instability windows and characterized in the resistance-potential parameter plane. The dynamic features of such oscillations suggest the existence of distinct mechanisms according to the potential region. Previously published results obtained under non-oscillatory regime were used to give some hints on the surface chemistry behind the observed dynamics. (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
• Processo FAPESP: 12/07313-1 - Eletro-oxidação de misturas de combustíveis: instabilidades cinéticas e mecanismo
• Beneficiário: Eduardo Giangrossi Machado
• Modalidade de apoio: Bolsas no Brasil - Doutorado