Estudo da reação de oxidação de etilenoglicol sobre eletrocatalisadores ternários

Abstract

The fuel cell is an energy device that has become a sustainable energy source that causes less impact on the environment, the main type of fuel used is hydrogen, applied in various sectors such as transport, an alternative to hydrogen is the use of alcohol in direct alcohol fuel cells (DAFC), which has advantages, for example, low emission of polluting gases. The use of ethylene glycol comes as an attempt to improve performance, it is the most suitable for having a theoretical energy density close to other types of alcohol, it is low cost and easy to store, in addition to offering low toxicity and less flammability. This work aims to study the occurrence of electro-oxidation of ethylene glycol on Pt-based ternary discussions with emphasis on catalytic activity that were prepared by the formic acid method. The tests were carried out using cyclic voltammetry in the presence of supporting electrolyte, in acid and alkaline media with a potential range between 0.6 and 1.8 V vs. ERH, scanning speed of 50 mV.s-1 and chronoamperometry at an applied potential of 0.6 V with an operating time of 3600 s, carried out at room temperature. The PtSnRh/C electrocatalyst demonstrated high catalytic activity in the occurrence of ethylene glycol electro-oxidation. In tests carried out in both alkaline and acidic environments, PtSnRh/C exhibited different catalytic performance in each environment, keeping the initial oxidation potential of ethylene glycol constant. An increase in current density in alkaline media was observed from 0.5 V, as confirmed in alternating current (AC) tests. Thus, PtSnRh/C presented active sites in oxidation and reduction processes that can be used for the oxidation of small organic molecules and their intermediates, as well as for the electro-oxidation of ethylene glycol.