Browsing by Author "Muena, J. P."

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    Carbon neutral electrochemical conversion of carbon dioxide mediated by [Mn+(cyclam)Cl-n] (M = Ni2+ and Co3+) on mercury free electrodes and ionic liquids as reaction media
    (2017) Honores Sotelo, Jessica Scarlet; Quezada Sandoval, Diego Alonso; García, M.; Calfuman, K.; Muena, J. P.; Aguirre, M. J.; Arévalo, M. C.; Isaacs Casanova, Mauricio; Honores Sotelo, Jessica Scarlet; Quezada Sandoval, Diego Alonso; García, M.; Calfuman, K.; Muena, J. P.; Aguirre, M. J.; Arévalo, M. C.; Isaacs Casanova, Mauricio
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    Electro-reduction of Oxygen to Water Mediated by Stable Glassy Carbon Electrodes Modified by Co(II)-porphyrins with Voluminous Meso-Substituent
    (2015) Marin, A., V; Aguirre, M. J.; Muena, J. P.; Dehaen, W.; Maes, W.; Ngo, Thien H.; Ramirez, G.; Arevalo, M. C.
    Glassy carbon electrodes were modified by physisorption of two different Co(II)-porphyrins, specifically designed and synthesized to study the effect of the substitution pattern (and the resulting steric hindrance) on the electrocatalytic behavior for a characteristic inner-sphere reaction such as the reduction of oxygen. In spite of the change in morphology caused by a change in the relative positions of the meso substituents, they showed practically the same behavior toward the electro-reduction of O-2. In both cases, water was obtained as the main product. The modified electrodes were also active toward the electro-reduction of hydrogen peroxide. Both electrodes were found stable for more than a month upon exposure to air and the current for the electro-reduction remained practically the same.
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    Electro-reduction of Oxygen to Water Mediated by Stable Glassy Carbon Electrodes Modified by Co(II)-porphyrins with Voluminous Meso-Substituent
    (2015) Marin, A.; Aguirre, M. J.; Muena, J. P.; Dehaen, W.; Maes, W.; Ngo, Thien H.; Ramírez Jofré, Galo; Arevalo, M. C.
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    ELECTROCHEMICAL METHOD FOR SULFITE DETERMINATION IN WINES BY ELECTROCHEMICAL RESPONSE USING A MEMBRANE ABSORBER SYSTEM
    (SOC CHILENA QUIMICA, 2016) Arce, Roxana; Baez, Carla; Muena, J. P.; Aguirre, Maria J.; Romero, Julio
    This research demonstrates how the sulfite content can be measured by cyclic voltammetry using a previously reported membrane absorber system, which separates efficiently sulfite present in wine. Results obtained show notably similar values to those obtained for the same wine samples using modified MonierWilliams method (aspiration method) and Ripper method. The membrane absorber system allows the release of the free SO2, and can be used to determine the sulfur dioxide present in juices and other foods that contain high concentrations of phenols, polyphenols and other structurally related compounds that act as interferers in the electrochemical oxidation of sulfite. The absorber solution allows a direct measurement without change in pH or added electrolyte, facilitating the determination of great amounts of samples from diverse wines using only one calibration curve. In this way, a system that allows the detection of sulfite and that can be used in vineyards is obtained.