Segregation and stability at Pt3Ni(111) surfaces and Pt75Ni25 nanoparticles

被引:60
作者
Fowler, Ben [1 ]
Lucas, Christopher A. [1 ]
Omer, Ahmed [1 ]
Wang, Guofeng [2 ]
Stamenkovic, Vojislav R. [3 ]
Markovic, Nenad M. [3 ]
机构
[1] Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England
[2] Univ S Carolina, Dept Chem & Phys, Aiken, SC 29801 USA
[3] Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA
基金
英国工程与自然科学研究理事会;
关键词
electrocatalysis; single crystal alloy; X-ray scattering; surface segregation; nanoparticles;
D O I
10.1016/j.electacta.2007.11.063
中图分类号
O646 [电化学、电解、磁化学];
学科分类号
081704 ;
摘要
Using in situ surface X-ray diffraction we have determined the atomic structure and stability of a Pt3Ni(111) surface in the electrochemical environment. Surface segregation leads to a pure Pt(111) skin with enrichment of Ni in the sub-surface atomic layer that determines the surface electronic structure. The Pt-skin surface exhibits inward relaxation upon the adsorption of oxygenated species and this explains the surface stability compared to pure Pt(111). Using Monte Carlo calculations it is shown that nanoparticles with the same surface composition and stochiometry are energetically stable. (C) 2007 Elsevier Ltd. All rights reserved.
引用
收藏
页码:6076 / 6080
页数:5
相关论文
共 24 条
[1]  
[Anonymous], SURFACE SCI REPORTS
[2]   A SUITE OF PROGRAMS FOR CALCULATING X-RAY ABSORPTION, REFLECTION, AND DIFFRACTION PERFORMANCE FOR A VARIETY OF MATERIALS AT ARBITRARY WAVELENGTHS [J].
BRENNAN, S ;
COWAN, PL .
REVIEW OF SCIENTIFIC INSTRUMENTS, 1992, 63 (01) :850-853
[3]   SURFACE-SANDWICH SEGREGATION ON NONDILUTE BIMETALLIC ALLOYS - PT50NI50 AND PT78NI22 PROBED BY LOW-ENERGY ELECTRON-DIFFRACTION [J].
GAUTHIER, Y ;
JOLY, Y ;
BAUDOING, R ;
RUNDGREN, J .
PHYSICAL REVIEW B, 1985, 31 (10) :6216-6218
[4]   PTXNI1-X(111) ALLOY SURFACES - STRUCTURE AND COMPOSITION IN RELATION TO SOME CATALYTIC PROPERTIES [J].
GAUTHIER, Y ;
BAUDOING, R ;
JOLY, Y ;
RUNDGREN, J ;
BERTOLINI, JC ;
MASSARDIER, J .
SURFACE SCIENCE, 1985, 162 (1-3) :342-347
[5]  
Hammer B., 1997, CHEMISORPTION REACTI
[6]   Role of strain and ligand effects in the modification of the electronic and chemical properties of bimetallic surfaces [J].
Kitchin, JR ;
Norskov, JK ;
Barteau, MA ;
Chen, JG .
PHYSICAL REVIEW LETTERS, 2004, 93 (15) :156801-1
[7]   Quasi-collective motion of nanoscale metal strings in metal surfaces [J].
Labayen, M ;
Ramirez, C ;
Schattke, W ;
Magnussen, OM .
NATURE MATERIALS, 2003, 2 (12) :783-787
[8]  
Lucas C. A., 2003, ENCY ELECTROCHEMISTR, V2
[9]   Surface relaxation at the metal/electrolyte interface [J].
Lucas, CA .
ELECTROCHIMICA ACTA, 2002, 47 (19) :3065-3074
[10]   Initial corrosion observed on the atomic scale [J].
Renner, FU ;
Stierle, A ;
Dosch, H ;
Kolb, DM ;
Lee, TL ;
Zegenhagen, J .
NATURE, 2006, 439 (7077) :707-710