Nanopartículas de platina com carvão ativado para eletro-oxidação de etanol

Abstract

Fuel cells have gained prominence in recent years due to their ability to generate clean energy, helping to mitigate problems related to the depletion of fossil fuels and the environmental degradation faced by society, such as CO2, CO, NOx, SOx, hydrocarbons and particulates, which are harmful to human health and responsible for acid rain and the greenhouse effect. Within this context, fuel cells of the DEFC (Direct Ethanol Fuel Cell) type, which use ethanol directly as fuel, have attracted growing interest, as the technology involved has significant advantages over the energy sources currently used. As well as being a renewable energy source, ethanol can be produced from biomass, making it a sustainable alternative for energy production. DEFCs not only reduce pollutant emissions, but also have greater energy efficiency and are able to operate at lower temperatures compared to other types of fuel cells. These characteristics make DEFCs a promising solution for the future of clean and sustainable energy generation. The present work studied the synthesis and characterization of the properties of platinum-based electrocatalysts (Pt) adsorbed on tucumã activated carbon (AC), specifically Pt/CA and PtSn/CA, using the formic acid method (MAF), where electrochemical analyses (cyclic voltammetry and chronoamperometry) were carried out to evaluate the profiles and determine which of the electrocatalysts performed best. In cyclic voltammetry, the voltammograms indicated that the PtSn/CA electrocatalyst outperformed the Pt/CA one. In PtSn/CA, platinum (Pt) played a crucial role in the dissociative adsorption of ethanol and its intermediates, while tin (Sn) contributed to the formation of oxygenated species at lower potentials. This behavior was confirmed by the chronoamperometry tests, where the tests carried out showed that both Pt-based electrocatalysts were effective for the electro-oxidation of ethanol.