Preparation of Pt rate earth/C electrocatalysts using the alcohol-reduction process ethanol electro-oxidation
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2008
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SPRING MEETING OF THE INTERNATIONAL SOCIETY OF ELECTROCHEMISTRY, 6th
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Fuel cell employing alcohols directly as combustible (Direct Alcohol Fuel Cell -
DAFC) are attractive as power sources for mobile, stationary and portable applications.
Compared to hydrogen-fed fuel cells which need a reforming system, or have hydrogen
storage problems, DAFC uses a liquid fuel simplifying the fuel system. Methanol has
been considered the most promising fuel, because it is more efficiently oxidized than
others alcohols, however, slow anode kinetics are observed and it is a toxic product.
Ethanol offers an attractive alternative in relation to methanol as a fuel in low
temperature fuel cells because it can be produced in large quantities from agricultural
products and it is the major renewable biofuel from the fermentation of biomass.
However, its complete oxidation to CO2 is more difficult than that of methanol due to
the difficulty in C–C bond breaking and to the formation of CO-intermediates that
poison the platinum anode catalysts. In this context, more active electrocatalysts are
essential to enhance the ethanol electro-oxidation. In recent years, it is found that
certain metal oxides, such as RuO2, SnO2 and CeO2, can enhance the catalytic activity
for ethanol or methanol electro-oxidation through synergetic interaction with Pt.
Among those, rare earth oxides exhibit a number of characteristics that make them
interesting for catalytic studies. In this work, Pt Rare Earth/C electrocatalysts (Rare
Earth = La, Ce, Pr, Nd, Sm, Tb, Dy, Ho Er, Tm and Lu) were prepared in a single
step by an alcohol reduction process using ethylene glycol as reduction agent and
solvent and Vulcan XC 72 as support. The obtained materials were tested for ethanol
oxidation in acid medium using cyclic voltammetry and chronoamperometry. The EDX
analysis showed that the Pt:RE atomic ratios obtained for all electrocatalysts were
approximately 60:40 and were similar to the ones used in the preparations. The X-ray
diffractograms of Pt Rare Earth/C electrocatalysts showed the typical fcc structure of
platinum and the presence of rare earth (III) hydroxides. The average particle size were
calculated using Scherrer equation using the reflections of Pt(220) peak and the values
are in the range of 6-15 nm. The final current values after holding the cell potential at
0.5V versus RHE for 30 min are following: PtLu/C> PtTb/C > PtEr/C ≈ PtNd/C ≈
PtCe/C > PtHo/C > PtLa/C >PtDy/C > PtTm/C > PtPr/C > PtSm/C > Pt/C. The
superior activity of Pt Rare Earth/C electrocatalysts in relation Pt/C could be attributed
probably to the bi-functional mechanism were Pt acts on ethanol adsorption and
dissociation and Rare Earth provides oxygenated species at lower potentials for
oxidative removal of adsorbed CO.
Como referenciar
RODRIGUES, RITA M. de S.; RIBEIRO, VILMARIA A.; BRANDALISE, MICHELE; TUSI, MARCELO M.; LINARDI, MARCELO; FORBICINI, CHRISTINA A.L.G.O.; SPINACE, ESTEVAM V.; OLIVEIRA, ALMIR. Preparation of Pt rate earth/C electrocatalysts using the alcohol-reduction process ethanol electro-oxidation. In: SPRING MEETING OF THE INTERNATIONAL SOCIETY OF ELECTROCHEMISTRY, 6th, March 16-19, 2008, Foz do Iguacu, PR. Abstract... Disponível em: http://repositorio.ipen.br/handle/123456789/19279. Acesso em: 30 Dec 2025.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.