The catalytic performance of metallic nanoparticles is highly correlated with their structure and size, and an understanding of their various phases, transitions and stability – particularly at high temperatures – is essential to understanding high temperature catalytic reactions. Ruthenium nanostructures are well known as a model catalytic system due to their high catalytic performance such as CO oxidation, hydrogenation, and ammonia synthesis. Moreover, recently was discovered existence of a metastable fcc structure in Ru nanoparticles, which does not exist in the bulk phase diagram, and which apparently survives up to 450oC [1]. In this work we present studies regarding the stability of Ru phases in nanostructures at temperatures as high as 800oC. We synthesized uniformly spherical and monodisperse ruthenium nanoparticles with average size of 2.5nm via an acetate-assisted polyol route. By varying precursors and reaction solvents, we were able to vary the ratio of Ru nanoparticles that have either primarily hcp or fcc structures. A study of the structural stability of metastable fcc Ru and detailed quantification of the size variations of both fcc and hcp Ru nanoparticles as determined environmental transmission electron microscopy (800°C in &gt; 1Torr Ar/H2 atmosphere) will be presented. 1. K.Kusada et. al., JACS 135, 5493 (2013) 2. "Research carried out in part at the Center for Functional Nanomaterials, Brookhaven National Laboratory, which is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886."

Chemical synthesis and High temperature structural stability of monodisperse ruthenium nanostructures

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.