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Electroreduction of oxygen on gold-supported thin Pt films in acid solutions
被引:25
作者:
Sarapuu, Ave
[1
]
Kallip, Silvar
[1
]
Kasikov, Aarne
[2
]
Matisen, Leonard
[2
]
Tammeveski, Kaido
[1
]
机构:
[1] Univ Tartu, Inst Chem, EE-51014 Tartu, Estonia
[2] Univ Tartu, Inst Phys, EE-51014 Tartu, Estonia
关键词:
Oxygen reduction;
Electrocatalysis;
Kinetic parameters;
Cold support;
Pt film;
Scanning tunnelling microscopy;
D O I:
10.1016/j.jelechem.2008.09.001
中图分类号:
O65 [分析化学];
学科分类号:
070302 ;
081704 ;
摘要:
The electrochemical reduction of oxygen was studied on vacuum evaporated thin Pt films (0.25-20 nm thick) on polycrystalline Au substrate (Pt/Au) in 0.1 M HClO4 and 0.05 M H2SO4 solutions using the rotating disk electrode (RDE) method. The surface morphology of Pt films was examined by scanning tunnelling microscopy (STM). The O-2 reduction specific activity of Pt films increased with increasing the film thickness in HClO4, but was lower than that of bulk Pt even for the thickest films. In H2SO4, the specific activity showed no significant dependence on the platinum loading and was lower than in HClO4. The Tafel slope values characteristic to polycrystalline Pt (-120 mV dec(-1) and -60 mV dec(-1)) were found for all electrodes. The RRDE studies of 0.5 nm Pt/Au electrode revealed that O-2 reduction predominantly proceeds through 4e(-) pathway and H2O2 is produced in low quantities. (C) 2008 Elsevier B.V. All rights reserved.
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页码:144 / 150
页数:7
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