Artigo de peri??dico
Fuel cell and electrochemical studies of the ethanol electro-oxidation in alkaline media using PtAuIr/C as anodes
Registro en:
9
23
10.1007/s11581-017-2088-8
48.800
Autor
SILVA, SIRLANE G. da
FONTES, ERIC H.
ASSUMP??AO, MONICA H.M.T.
LINARDI, MARCELO
SPINACE, ESTEVAM
SILVA, JULIO C.M.
OLIVEIRA NETO, ALMIR
Resumen
Ethanol electro-oxidation reaction was investigated
considering conventional electrochemical experiments in alkaline
media, direct ethanol fuel cell (DEFC), and in situ ATRFTIR.
The working electrode/anodes were composed of monometallic
Pt/C, Au/C, Ir/C, and trimetallic PtAuIr/C nanoparticles
with atomic Pt/Au/Ir ratios of 40:50:10, 50:40:10, 60:30:10,
70:20:10, and 80:10:10. X-ray diffraction (XRD) suggests
PtAuIr/C alloy formation, and according to transmission electron
micrographs, the mean particle sizes are from 4 to 6 nm for all
catalyst compositions. PtAuIr/C 40:50:10 showed the highest
catalytic activity for ethanol electro-oxidation in the electrochemical
experiments; using this material, the peak current density
from ethanol electro-oxidation on cyclic voltammetry experiment
was 50 mA per g of Pt, 3.5 times higher than that observed
with Pt/C. The fuel cell performance was superior using all
PtAuIr/C compositions than using Pt/C. Au/C and Ir/C presented
very poor catalytic activity toward ethanol electro-oxidation. The
improved results obtained using PtAuIr/C might be related to the
OHads species formed at low overpotential on Ir and to the decrease
on adsorption energy of poisoning intermediates on Pt
sites, promoted by Au. Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) FAPESP: 14/09087-4; 14/50279-4