Surface segregation and stability of core-shell alloy catalysts for oxygen reduction in acid medium

被引：111

作者：

Ramirez-Caballero, Gustavo E. ^{[1
,2
]}

Ma, Yuguang ^{[1
]}

Callejas-Tovar, Rafael ^{[1
]}

Balbuena, Perla B. ^{[1
]}

机构：

[1] Texas A&M Univ, Dept Chem Engn, College Stn, TX 77843 USA

[2] Univ Ind Santander, Dept Ingn Quim, Bucaramanga, Colombia

来源：

PHYSICAL CHEMISTRY CHEMICAL PHYSICS | 2010年 / 12卷 / 09期

关键词：

INITIO MOLECULAR-DYNAMICS; PLATINUM-MONOLAYER ELECTROCATALYSTS; TOTAL-ENERGY CALCULATIONS; ATOMIC OXYGEN; PT3M ALLOYS; TRANSITION; METAL; DISSOLUTION; DURABILITY; ABSORPTION;

D O I：

10.1039/b917899f

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Density functional theory is used for the evaluation of surface segregation, trends for dissolution of Pt surface atoms in acid medium, and oxygen reduction reaction activity of core-shell materials, containing a monolayer of platinum over a monometallic or bimetallic core. Two groups of cores are investigated: Pt/X with X = Ir, Au; Pd, Rh, Ag; Co, Ni, Cu; and Pt/Pd3X, with X = Co, Fe, Cr, V, Ti, Ir, Re. It is found that all the 4d and 5d pure cores may serve as stable cores, and their beneficial effect on the Pt monolayer may be further tuned by alloying the core to another element, here chosen from 3d or 5d groups. The Pd3X cores enhance the stability of the surface Pt atoms both in vacuum and under adsorbed oxygen; however the high oxygen philicity of some of the X elements induces their surface segregation that may cause surface poisoning with oxygenated species and their dissolution in acid medium.

引用

页码：2209 / 2218

页数：10

共 68 条

[11] Absolute composition depth-profiles in surface segregation of Pt-Rh alloys [J].

Florencio, J ;

Ren, DM ;

Tsong, TT .

SURFACE SCIENCE, 1996, 345 (03) :L29-L33

[12] LEIS AND AES ON SPUTTERED AND ANNEALED POLYCRYSTALLINE PT-RU BULK ALLOYS [J].

GASTEIGER, HA ;

ROSS, PN ;

CAIRNS, EJ .

SURFACE SCIENCE, 1993, 293 (1-2) :67-80

[13] LEED STUDY OF PT25CO75(111) [J].

GAUTHIER, Y ;

BAUDOINGSAVOIS, R ;

ROSINK, JJWM ;

SOTTO, M .

SURFACE SCIENCE, 1993, 297 (02) :193-201

[14] Electrochemical dissolution of surface alloys in acids: Thermodynamic trends from first-principles calculations [J].

Greeley, J. ;

Norskov, J. K. .

ELECTROCHIMICA ACTA, 2007, 52 (19) :5829-5836

[15] Alloy catalysts designed from first principles [J].

Greeley, J ;

Mavrikakis, M .

NATURE MATERIALS, 2004, 3 (11) :810-815

[16] Atomic oxygen absorption into Pt-based alloy subsurfaces [J].

Gu, Zhihui ;

Balbuena, Perla B. .

JOURNAL OF PHYSICAL CHEMISTRY C, 2008, 112 (13) :5057-5065

[17] Chemical environment effects on the atomic oxygen absorption into pt(111) subsurfaces [J].

Gu, Zhihui ;

Balbuena, Perla B. .

JOURNAL OF PHYSICAL CHEMISTRY C, 2007, 111 (46) :17388-17396

[18] Absorption of atomic oxygen into subsurfaces of Pt(100) and Pt(111): Density functional theory study [J].

Gu, Zhihui ;

Balbuena, Perla B. .

JOURNAL OF PHYSICAL CHEMISTRY C, 2007, 111 (27) :9877-9883

[19] Dissolution of oxygen reduction electrocatalysts in an acidic environment: Density functional theory study [J].

Gu, Zhihui ;

Balbuena, Perla B. .

JOURNAL OF PHYSICAL CHEMISTRY A, 2006, 110 (32) :9783-9787

[20] A fast and robust algorithm for Bader decomposition of charge density [J].

Henkelman, Graeme ;

Arnaldsson, Andri ;

Jonsson, Hannes .

COMPUTATIONAL MATERIALS SCIENCE, 2006, 36 (03) :354-360

← 1 2 3 4 5 6 7 →