کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1292730 | 973395 | 2006 | 5 صفحه PDF | دانلود رایگان |
Carbon supported ruthenium-based catalysts (Ru/C) for the oxygen reduction in acid electrolytes were investigated. A treatment of Ru/C catalysts with selenious acid had a beneficial effect on catalytic activity but no influence on intrinsic kinetic properties, like Tafel slope and hydrogen peroxide generation. Reasons for the increased activity of RuSex/C catalysts are discussed. Potential step measurements suggest that at potentials around 0.8 V (NHE) a selenium or selenium-oxygen species protects the catalyst from formation of inactive RuO2-films. This protective effect leads to an enhanced activity of RuSex/C compared to Ru/C. No evidence was found for a catalytically active stoichiometric selenium compound. The active phase may be described as a ruthenium suboxide RuOx (x < 2) layer integrated in a RuSey phase or RuSeyOv (y < 2, v < 2) layer at the particle surface.
Journal: Journal of Power Sources - Volume 155, Issue 1, 18 April 2006, Pages 47–51