Size and composition control of Pt-In nanoparticles prepared by seed-mediated growth using bimetallic seeds.
A two-step method has been developed for precise size and composition control of bimetallic Pt-In nanoparticles. Very small (1.62 nm) PtIn seed nanoparticles with 1:1 metal ratio were prepared in the absence of capping agents followed by growth of Pt on their surface in the presence of oleyl amine as reducing and stabilizing agent. Nanoparticles with bulk compositions of Pt(4)In, Pt(3)In, and Pt(2)In could be synthesized with average diameter smaller than 3 nm. TEM, EDX, and XPS provided evidence for homogeneous growth without separate nucleation of pure platinum nanoparticles in the reaction solution. Pt(3)In nanoparticles were deposited onto SiO(2) surface by incipient wetness impregnation. Temperature-induced changes in the particle surface were monitored by in situ IR spectroscopy and CO adsorption. It was found that surface alloy composition of the particles could be tuned by using oxidizing or reducing atmospheres.
Department of Chemical and Biomolecular Engineering, 201 Gilman Hall, University of California, Berkeley, California 94720-1462, USA.
Ferenc
F
Somodi
Sebastian
S
Werner
Zhenmeng
Z
Peng
Andrew Bean
AB
Getsoian
Anton N
AN
Mlinar
Boon Siang
BS
Yeo
Alexis T
AT
Bell