Artigo de peri??dico
Structural analysis of PdRh/C and PdSn/C and its use as electrocatalysts for ethanol oxidation in alkaline medium
Registro en:
0360-3199
2
44
10.1016/j.ijhydene.2018.11.049
0000-0001-8745-3421
73.237
88.25
Autor
FONTES, ERIC H.
RAMOS, CARLOS E.D.
NANDENHA, JULIO
PIASENTIN, RICARDO M.
OLIVEIRA NETO, ALMIR
LANDERS, RICHARD
Resumen
The Pd/C, PdRh(50:50)/C and PdSn(50:50)/C nanomaterials were used as electrocatalysts for
ethanol (EtOH) oxidation in Direct Ethanol Fuel Cell (DEFC) in an alkaline medium. This
work aims to provide a complete physical characterization of the nanomaterials, elucidate
the bifunctional mechanism concerning ethanol oxidation reaction and understand the
influence of carbon e metal bonding in the electrochemical activity. These nanomaterials
were investigated by X-ray photoelectron spectroscopy (XPS) and revealed that the atomic
percentage of the surface is different of those obtained by Energy Dispersive X-ray spectroscopy
(EDS). Raman spectroscopy showed a bonding between palladium and carbon
atoms which can play a decisive role in the performance of the materials. Attenuated Total
Reflectance technique coupled to the Fourier Transform Infrared spectroscopy (ATR-FTIR)
made possible to investigate the oxidation products originated by the ethanol oxidation,
and all the electrocatalysts showed the presence of acetaldehyde, carbonate ions, acetate
and carbon dioxide, suggesting that the mechanism of oxidation is incomplete. Among all
the nanomaterials studied, PdSn(50:50)/C showed the best electrochemical and Fuel Cell's
results. It is about 33% better than Pd/C. The micrographs obtained by Transmission
Electron Microscopy (TEM) revealed some agglomerate regions, but they are consistent
with the literature data.