Produção de compostos de alto valor agregado a partir da eletro-oxidação de glicerol por vias eletroquímicas utilizando nanopartículas de Pt/C decoradas com Ru

Abstract

The growing energy demand has initiated many researches on energy conversion technologies that result in the least possible environmental impact. Among these technologies studied are the fuel cells, for which the biomass derivatives appear as promising fuels for anode feed. Many researches show glycerol as a strong candidate as a fuel for fuel cells, since its complete oxidation produces 14 electrons and is generated on a large scale as a by-product of biodiesel production. The great challenge is to synthesize catalysts that can oxidize the molecule completely, since the limited cleavage of the C-C bonds leads to the formation of glycerol partial oxidation products, which decreases the efficiency of the device. However, this obstacle represents an opportunity for the concomitant use of glycerol as fuel and to generate organic compounds with high added value. To obtain selectivity in the glycerol electrooxidation reaction, it is necessary to control the electrochemical environment and to know the characteristics of the catalyst. Much effort has been spent to develop multimetallic catalysts in order to improve the electrocatalytic and selectivity properties. In this context, we developed a new strategy to decorate nanoparticles with ad-atoms based on a cell in wall-jet configuration coupled to an electronic micropipette which is fast, economical and accurate. Using the developed method, we produced Ru/Pt/C catalysts with different coverage degrees. The catalytic activity and the selectivity of the glycerol electro-oxidation reaction were investigated. By using electrochemical measurements, we have determined that Ru/Pt/C nanoparticles with intermediate coverage degrees present high stability, high current density and low onset potential. Additionally, the analysis of glycerol electrooxidation products by high performance liquid chromatography showed that the catalyst can produce glyceraldehyde, glycolic acid, formic acid, dihydroxyacetone, mesoxalic acid and hydroxypyruvic acid. Thus, we concluded that intermediate Ru coverage degrees facilitate the glycerol electrooxidation reaction, but the selectivity seems not affected.