Nanostructured electrocatalysts based on PT, PD and oxides of low cost for applications in energy and environment

Abstract

Environmental impacts, damage to health and depletion of non-renewable energy sources have motivated research in the area of energy, with the purpose of seeking alternatives to supply the energy demand needed, minimizing damages caused by currently used sources such as oil. With this, it is possible to apply devices such as fuel cells to provide energy in a clean and efficient way. This project aims to develop platinum and palladium based electrocatalysts with the use of auxiliary metal oxides such as tin, cerium and iron, which improve the activity and reduce the costs of noble metals, for the oxidation of fuels as ethanol and acetol in DLFC's (Direct Liquid Fuel Cells). The use of ethanol is interesting due to its green characteristics, because it is a renewable source, besides economic viability, since Brazil is one of the largest producers of ethanol worldwide. The interest in the use of acetol as fuel is the innovation of this project, since this molecule has not yet been used in electrochemical oxidation systems, and presents great environmental viability, because it is a compound derived from glycerol, this one obtained from the biodiesel. The control of the morphology of the electrocatalysts will be approached (nanodendrites, nano-octahedrons, nanobarras), according to the synthesis used in obtaining the metallic nanoparticles, and will use different substrates based on carbonaceous materials (carbon, graphene and carbon nanotubes), and studied their respective contributions in the activity of the electrocatalyst. For the physical characterization of the electrocatalysts, specific techniques will be used, such as: X-ray Diffraction (XRD), Dispersive Energy Spectroscopy (DES), Scanning Electron Microscopy (SEM), Electron Transmission Electron Microscopy (MET), and Photoelectron Spectroscopy of X-ray (XPS). Cyclic Voltammetry and Cronoamperometry experiments will also be carried out for electrochemical characterization and evaluation of the electrocatalytic activity, as well as the verification of the products formed by Infra-Red Fourier Transform (FTIR in situ) spectroscopy. The application of the electrocatalysts in a unit fuel cell, for the oxidation of ethanol and acetol (not yet studied in the literature to our knowledge), will be carried out by electrochemical experiments mentioned above, to evaluate the activity and increase in the performance and efficiency of such devices due to nanostructures and supports used. Also with the environmental bias will be applied cerium oxide nanobarras for the degradation of organic pollutants (17b estradiol) by means of advanced oxidative electrochemical processes. (AU)