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Titolo:
CO Tolerance of Pt alloy electrocatalysts for polymer electrolyte fuel cells and the detoxification mechanism
Autore:
Igarashi, H; Fujino, T; Zhu, YM; Uchida, H; Watanabe, M;
Indirizzi:
Yamanashi Univ, Fac Engn, Lab Electrochem Energy Convers, Kofu, Yamanashi 4008511, Japan Yamanashi Univ Kofu Yamanashi Japan 4008511 ofu, Yamanashi 4008511, Japan
Titolo Testata:
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
fascicolo: 3, volume: 3, anno: 2001,
pagine: 306 - 314
SICI:
1463-9076(2001)3:3<306:CTOPAE>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
CARBON-MONOXIDE OXIDATION; ADSORBING AD-ATOMS; PT-RU ALLOYS; INFRARED-SPECTROSCOPY; PLATINUM-ELECTRODE; DOUBLE-LAYER; VIBRATIONAL SPECTROSCOPY; H-2/CO MIXTURES; ELECTROOXIDATION; ENHANCEMENT;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
41
Recensione:
Indirizzi per estratti:
Indirizzo: Igarashi, H Yamanashi Univ, Fac Engn, Lab Electrochem Energy Convers, Takeda 4-3, Kofu, Yamanashi 4008511, Japan Yamanashi Univ Takeda 4-3 Kofu Yamanashi Japan 4008511 , Japan
Citazione:
H. Igarashi et al., "CO Tolerance of Pt alloy electrocatalysts for polymer electrolyte fuel cells and the detoxification mechanism", PHYS CHEM P, 3(3), 2001, pp. 306-314

Abstract

The electrocatalytic activity for H-2 oxidation in the presence of 100 ppmCO has been investigated on a series of binary Pt alloy electrocatalysts with non-precious metals of various compositions. Regardless of the composition, Pt-Fe, Pt-Ni, Pt-Co and Pt-Mo alloys have been found to exhibit excellent CO tolerance in H-2 oxidation, similar to that of the Pt-Ru alloy. At these CO-tolerant electrodes, the equilibrium coverage of CO was suppressed to values less than ca. 0.6. Based on X-ray photoelectron spectroscopy (XPS) data, it was found that the surfaces of all non-precious metal alloys arecomposed of a thin Pt layer with an electronic structure different from that of pure Pt, indicating an increased 5d vacancy of Pt in the layers of the CO-tolerant alloys. The CO coverage, particularly with multi-bonding, waslowered due to decreased electron donation from the Pt band to the 2 pi* orbital of CO. A weakening of bond strength between the Pt skin layer and COwas also indicated by in situ FTIR, suggesting that the H-2 oxidation sites are not blocked by CO due to its enhanced mobility. Thus, the mechanism of CO tolerance described above at the Pt skin on alloy surfaces is proposedas a "detoxification mechanism''.

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Documento generato il 29/03/20 alle ore 15:43:32