Ethanol is a promising candidate as fuel in polymer electrolyte fuel cells for application on portable electronic devices. In addition to the production and distribution network already existent in Brazil, the ethanol is a renewable fuel, which is important for the sustainability. Other advantage is its high energy content that corresponds to 12 electrons per ethanol molecule for its total oxidation to CO2. A high active electrocatalyst for the total ethanol electro-oxidation has to present a good performance for the steps C-H, C-C and O-H bond breaking, and C-O bond formation. Pt has presented the highest activity among the pure metals due to its better balance between the opposite trends of bond breaking and bond formation mentioned above, but its activity can be further increased by the modification of its electronic structure, and by the insertion of one or more metals that present higher activity for particular reaction steps. Nevertheless, little is know about the quantitative distribution of the reaction products, mainly for bi and trimetallic catalysts. Therefore, the aims of this project are related to the synthesis and characterization of bi and trimetallic nanostructured electrocatalysts formed by Pt in combination with Rh and with metal oxides, such as SnOx and PbOx. The quantitative conversion efficiency of ethanol to the different reaction products will be performed by on-line mass spectrometry using electrochemical half-cell and unit fuel cells with stagnant and flow electrolytes. The final objective is to elucidate the relation between the electrocatalyst composition and structure with the activity, efficiency and stability for the ethanol electro-oxidation. The results will be used as a base for the construction of passive direct ethanol fuel cell for the application on portable electronic devices.
News published in Agência FAPESP Newsletter about the scholarship: