Methanol electrooxidation was investigated on tailored Pt-Ru-polyaniline catalysts prepared applying dynamic potential routines. The electrodes characterized by SEM, EDX and TEM present a uniform distribution of metal particles about 100 nm in size, composed of Ru and Pt on the fibrous polymer matrix. The effect of concentration in the range 0.05-1 M and temperature in the range 20 to 60 ºC on the methanol electrooxidation rate was determined. The apparent activation energy depends on the catalyst Ru content.

O comportamento eletroquímico na oxidação do etileno em superfícies de Au preferencialmente orientado é investigado em solução aquosa 1 M H2SO4 a 25°C. Uma onda quadrada de potencial simétrica e periódica é aplicada a eletrodos policristalinos de Au para obter superfícies orientadas dos tipos (111), (110) e (100), as quais são caracterizadas por voltamogramas cíclicos e micrografias SEM. É comprovado que o etileno se adsorve em potenciais ligeiramente inferiores ao potencial de carga zero da interface Au/1 M H2SO4, e dois resíduos são detectados num experimento de "stripping" anódico. A eletro-oxidação voltamétrica do etileno adsorvido e as curvas de polarização anódicas do etileno no meio da solução são medidas nas diferentes superfícies orientadas do Au.

The electrochemical behavior of ethylene electrooxidation on preferentially oriented Au surfaces is investigated in 1 M H2 SO4 aqueous solution at 25°C. A symmetric square wave periodic potential signal is applied to polycrystalline Au electrodes to obtain (111)-, (110)-, and (100)-type oriented surfaces, which are characterized by cyclic voltammograms and SEM micrographs. It is found that ethylene adsorbs at potentials just below the potential of zero charge of the Au/1 M H2 SO4 interface, and two residues are detected in an anodic stripping experiment. The adsorbed ethylene voltammetric electrooxidation, and the bulk ethylene anodic polarization curves are measured at the differently oriented Au surfaces.