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Surface segregation and reconstructive behaviour of the (100) and (110) surfaces of platinum–palladium bulk alloy single crystals: a voltammetric and LEED/AES study
- Source :
- Surface Science. 515:87-93
- Publication Year :
- 2002
- Publisher :
- Elsevier BV, 2002.
-
Abstract
- Using a modification of the Clavilier crystal preparation method, a series of palladium–platinum (1 0 0) and (1 1 0) single crystal alloy electrodes have been prepared covering the bulk composition range 3% [1] . Voltammetric data displayed systematic changes as a function of bulk palladium composition. These changes could be related to a gradual increase in the population of surface terrace sites by randomly distributed palladium atoms leading to attenuation of voltammetric peaks associated with platinum terraces. It was found also that at certain alloy compositions, the addition of palladium was sufficient to suppress the reconstruction characteristics of the pure platinum (1 0 0) and (1 1 0) surfaces. It was also established that palladium strongly surface segregates. Furthermore, the segregation was surface structure dependent with the more open (1 1 0) surfaces exhibiting greater segregation than the closer-packed (1 0 0) and (1 1 1) surfaces for a fixed bulk single crystal alloy composition. On the basis of these results, it is proposed that the surface segregation characteristics of platinum–palladium alloys are controlled by thermodynamics and that the composition of the selvedge region plays a crucial role in disfavouring surface reconstruction.
- Subjects :
- Auger electron spectroscopy
education.field_of_study
Alloy
Population
chemistry.chemical_element
Surfaces and Interfaces
engineering.material
Condensed Matter Physics
Surfaces, Coatings and Films
Crystal
Crystallography
chemistry
Materials Chemistry
engineering
Platinum
education
Single crystal
Surface reconstruction
Palladium
Subjects
Details
- ISSN :
- 00396028
- Volume :
- 515
- Database :
- OpenAIRE
- Journal :
- Surface Science
- Accession number :
- edsair.doi...........c7fe5d284ebf4ea61570a55db4c6fc43