Core shell inversion during nucleation and growth of bimetallic Pt/Ru nanoparticles

被引：190

作者：

Nashner, MS

Frenkel, AI

Somerville, D

Hills, CW

Shapley, JR ^{[1
]}

Nuzzo, RG

机构：

[1] Univ Illinois, Sch Chem Sci, Urbana, IL 61801 USA

[2] Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 1998年 / 120卷 / 32期

关键词：

D O I：

10.1021/ja980638z

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The reductive condensation of a carbon-supported molecular cluster precursor, PtRu5C(CO)is, into a bimetallic nanoparticle has been followed by using in situ extended X-ray absorption fine structure spectroscopy, temperature-programmed desorption, and scanning transmission electron microscopy. The data reveal that during activation in hydrogen the metal centers associated with the molecular precursor lose the stabilizing CO shell and assume. an increasingly metallic electronic character. This support-mediated condensation process is highly activated. The incipient Pt-Ru nanoparticles initially form a disordered structure at 473 K in which Pr is found preferentially at the core of the condensing particle. After further high-temperature treatment to 673 K, the nanoparticles adopt an inverted structure in which Pt appears preferentially at the surface of the equilibrated bimetallic nanoparticle.

引用

页码：8093 / 8101

页数：9

共 39 条

[1] CLUSTER SYNTHESIS .41. NEW PLATINUM RUTHENIUM CLUSTER COMPLEXES FROM THE REACTION OF PHCCPH WITH PT2RU4(CO)18 - SYNTHESIS AND STRUCTURAL CHARACTERIZATIONS OF PT2RU3(CO)8(MU-3-ETA-2-PHC2PH)2(MU-4-ETA-2-PHC2PH), PT3RU6(CO)14(MU-3-ETA-2-PHC2PH)3, PT2RU4(CO)14(MU-3-ETA-2-PHC2PH)(MU-4-ETA-2-PHC2PH), PT3RU6(CO)18(MU-3-ETA-2-PHC2PH)3, AND PTRU2(CO)6(MU-3-ETA-2-PHC2PH)(DPPE) [J].