Chemical state of ruthenium submonolayers on a Pt(111) electrode

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• 作者：Kim ; H. ; Rabelo de Moraes ; I. ; Tremiliosi-Filho ; G. ; Haasch ; R. ; Wieckowski ; A.
• 关键词：Alcohols ; Oxidation ; Electrochemical methods ; Catalysis ; Platinum ; Ruthenium ; Single crystal surfaces ; X-ray photoelectron spectroscopy
• 刊名：Surface Science
• 出版年：2001
• 出版时间：March 1, 2001
• 年：2001
• 卷：474
• 期：1-3
• 页码：L203-L212
• 全文大小：383 K

文摘

Oxidation states of ruthenium on a Pt(111)/Ru electrode were investigated by X-ray photoelectron spectroscopy. Ruthenium was added to platinum by electrochemical deposition methods: spontaneous deposition and electrolysis. Depending on the electrode potential, deposition conditions, and presence/absence of methanol in solution, metallic ruthenium (3d_5/2 core-level binding energy of 280.3 eV), RuO₂ (280.9 eV), and RuO₃ (282.8 eV) were found on the surface. After correlating ruthenium valence states to methanol oxidation reactivity, we concluded that the presence of a Ru metallic phase – covered by a weakly bonded Ru oxidation precursor – was a prerequisite for effective methanol oxidation electrocatalysis. This precursor was most likely “activated” water supplying the oxygen needed for transformation of surface CO to CO₂ at the edge of ruthenium islands on the Pt substrate.