Artigo de peri??dico
High activity of Pt???Rh supported on C???ITO for ethanol oxidation in alkaline medium
Registro en:
0922-6168
2
46
10.1007/s11164-019-04050-5
0000-0001-8745-3421
48.03
70.00
Autor
CAMARGO, V.F. de
FONTES, E.H.
NANDENHA, J.
SOUZA, R.F.B. de
NETO, A.O.
Resumen
PtRh/C???ITO electrocatalysts were prepared in a single-step method using
H2PtCl6
??6H2O and RhCl3
??xH2O as metal sources, sodium borohydride as the reducing
agent and a physical mixture of 85% Vulcan Carbon XC72 and 15% In2O3
??SnO2
(indium tin oxide???ITO) as support. PtRh/C???ITO were characterized by X-ray diffraction,
transmission electron microscopy, X-ray photoelectron spectroscopy (XPS),
cyclic voltammetry, chronoamperommetry, attenuated total reflectance, Fourier
transform infrared spectroscopy and performance test on direct alkaline ethanol fuel
cell. X-ray diffraction patterns for all PtRh/C???ITO indicated a shift in Pt (fcc) peaks,
showing that Rh was incorporated into Pt lattice. Transmission electron microscopy
for PtRh/C???ITO showed nanoparticles homogeneously distributed over the support
with particles size between 3.0 and 4.0 nm. The XPS results for Pt70Rh30/C???ITO
showed the presence of mixed oxidation states of Sn0
and SnO2
that could favor the
oxidation of adsorbed intermediates by bifunctional mechanism. Pt90Rh10/C???ITO
was more active in electrochemical studies, which could be associated with the C???C
bond break. Experiments in direct alkaline ethanol fuel cells showed that the power
density values obtained for Pt70Rh30/C???ITO and Pt90Rh10/C???ITO were higher
than Pt/C, indicating the beneficial effect of Rh addition to Pt and the use of C???ITO
support. Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq) FAPESP: 14/09087-4; 14/50279-4; 17/11937-4 CNPq: 300816/2016-2