Structural Characterization and Phase Behavior in Supported Metallic Nanoparticles

The reductive condensation of a carbon-supported molecular cluster precursor, PtRu5C(CO)16, 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 stabilizing CO shell is lost, and the metal centers assume an increasingly metallic electronic character. The incipient Pt-Ru nanoparticles initially form a disordered structure at 473 K in which Pt 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. (Abstract shortened by UMI.).

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Hills, Charles West

Contributors dc:contributor

• Nuzzo, Ralph G.

• Chemistry, Analytical

Language dc:language

eng

Identifier

(MiAaPQ)AAI3023073

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/84039