Ni microspheres as electrocatalysts for ethanol oxidation in an alkaline medium
We report the synthesis of nickel microspheres and their structural and electrochemical characterization. The materials were prepared by the microemulsion technique from NiSO4∙6H2O and NaOH, and using NaH2PO2∙H2O as a reducing agent. Sodium dodecyl sulfate (SDS) was used as a surfactant. The followi...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2018 |
| País: | México |
| Institución: | Centro de Investigación Científica de Yucatán |
| Repositorio: | Repositorio Institucional CICY |
| Idioma: | inglés |
| OAI Identifier: | oai:cicy.repositorioinstitucional.mx:1003/1545 |
| Acceso en línea: | http://cicy.repositorioinstitucional.mx/jspui/handle/1003/1545 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/Autores/NICKEL MICROSPHERES info:eu-repo/classification/Autores/MICROEMULSION SYNTHESIS info:eu-repo/classification/Autores/ELECTROCATALYSTS info:eu-repo/classification/Autores/ANODE info:eu-repo/classification/Autores/ALKALINE DIRECT ALCOHOL FUEL CELLS info:eu-repo/classification/cti/7 |
| Sumario: | We report the synthesis of nickel microspheres and their structural and electrochemical characterization. The materials were prepared by the microemulsion technique from NiSO4∙6H2O and NaOH, and using NaH2PO2∙H2O as a reducing agent. Sodium dodecyl sulfate (SDS) was used as a surfactant. The following ternary formulations were used for their synthesis: N1 (90%H2O-7.5%SDS-2.5%Pentanol), N2 (92.5%H2O-5%SDS-2.5%Pentanol), N3 (95%H2O-3.75%SDS-1.25%Pentanol) and N4 (99%H2O-0.75%SDS-0.25%Pentanol). The catalysts were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The catalytic activity for ethanol oxidation in an alkaline medium was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The average diameters of the nickel microspheres ranged from 0.375 to 1.476 m. On subjecting the materials to heat treatment in a nitrogen atmosphere at 300 °C for 4 h, mixtures of polycrystalline Ni and nickel phosphide (Ni3P) were obtained. The best performance for the ethanol oxidation reaction (EOR) in an alkaline medium was recorded with non-heat-treated nickel microspheres, presenting a maximum peak potential at approximately 0.7 V vs. Hg/HgO with normalized currents between 10.774 and 18.198 mA(mgcat)-1. These results indicate that nickel microspheres are potential candidates for use as anodes in alkaline direct alcohol fuel cells (A-DAFCs). |
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