A Coverage-Dependent Study of Pt Spontaneously Deposited onto Au and Ru Surfaces: Direct Experimental Evidence of the Ensemble Effect for Methanol Electro-Oxidation on Pt
- 1 September 2005
- journal article
- Published by American Chemical Society (ACS) in The Journal of Physical Chemistry B
- Vol. 109 (38), 17775-17780
- https://doi.org/10.1021/jp0537310
Abstract
Direct experimental evidence that can be unambiguously attributed to the need of an ensemble of a minimum number of neighboring Pt atoms for methanol electro-oxidation has been observed for the first time. This was realized by a Pt coverage-dependent investigation of methanol and CO electro-oxidation on Pt sites generated via spontaneous deposition onto both Au and Ru surfaces. CO stripping voltammograms also show clear evidence of a substantially strengthened CO−Pt bonding for submonolayer Pt deposited on the Au substrate over a range of ca. 0.22 to 0.77, which is in qualitative agreement with the theoretical prediction based on the Hammer−Nørskov d-band center model. However, the degree of the bond strengthening depends on the Pt coverage, being stronger for lower coverage. Additionally, evidence of an Ostwald ripening process for Pt islands formation has also been observed.Keywords
This publication has 21 references indexed in Scilit:
- Pt submonolayers on metal nanoparticles—novel electrocatalysts for H2 oxidation and O2 reductionElectrochimica Acta, 2003
- Electrosorption and catalytic properties of bare and Pt modified single crystal and nanostructured Ru surfacesJournal of Electroanalytical Chemistry, 2002
- Spontaneous deposition of Pt on the Ru(0001) surfaceJournal of Electroanalytical Chemistry, 2001
- How a gold substrate can increase the reactivity of a Pt overlayerSurface Science, 1999
- Mechanism and electrocatalysis in the direct methanol fuel cellCatalysis Today, 1997
- Surface electronic structure and reactivity of transition and noble metals1Communication presented at the First Francqui Colloquium, Brussels, 19–20 February 1996.1Journal of Molecular Catalysis A: Chemical, 1997
- CO Chemisorption at Metal Surfaces and OverlayersPhysical Review Letters, 1996
- Carbon monoxide electrooxidation on well-characterized platinum-ruthenium alloysThe Journal of Physical Chemistry, 1994
- Methanol electrooxidation on well-characterized platinum-ruthenium bulk alloysThe Journal of Physical Chemistry, 1993
- The oxidation of small organic moleculesJournal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1988