Affordable Access

O efeito da ordenação e estrutura geométrica dos materiais PtSn/C e PdSn/C na eletrooxidação do glicerol em meio alcalino

Authors
  • Bortoloti, Francielle
Publication Date
Mar 24, 2016
Source
Repositório Institucional UNESP
Keywords
Language
Portuguese
License
Unknown
External links

Abstract

Nowadays, the huge amount of glycerol produced from biodiesel obtaining process becomes an important environmental concern in our country. So, development of new and improvement of ancient methods of using glycerol urges to avoid the unappropriated discard of this compound and the consequent environmental pollution. Among the several methods early proposed, the enhancement of electrode materials able to electrooxidize glycerol appears as viable alternative to produce energy and/or high aggregated value chemicals. In the present work, it was investigated the performance of ordered intermetallic nanoparticles PtSn/C and PdSn/C and the alloys PtSn/C and Pd/Sn/C as anode materials to electrooxidize glycerol molecule in alkaline medium. The physical-chemical characterization of the synthesized nanoparticles was performed by using X-Ray Diffraction, Energy-Dispersive Spectrometry, High Resolution Transmission Electronic Microscopy and X-ray Absorption Spectroscopy techniques. The physical-chemical characterization confirmed the prevalence of ordered intermetallic structure from the synthetic route via polyol-modified protocol as well as the alloy structure prevalence as the materials were synthesized via micro-emulsion protocol. The electrochemical performance of the materials was investigated by using cyclic voltammetry and chronoamperometry techniques. All materials proved to be active for the glycerol electrooxidation reaction and it was observed the superior performance of the materials based on Pt as compared to the similar ones based on Pd. Moreover, ordered intermetallic PtSn/C presented the best performance among all the studied materials, which was proposed to be a consequence of the electronic effect of the neighbor Sn atom towards the Pt adsorption site. From mass spectra analysis, glyceraldehyde, glycolic acid and formic acid were detected as main products as the electrooxidation took place at Pt surfaces, evidencing the C-C bond cleavage. On the other hand, the same phenomenon was not observed for the reaction at Pd materials and the main products detected were glyceraldehyde or dihydroxyacetone for ordered intermetallic PdSn/C and tartronic acid for PdSn/C alloy. The corresponding electrooxidation mechanisms were proposed for the reaction occurring on all materials.

Report this publication

Statistics

Seen <100 times