AVS 49th International Symposium
    Electrochemistry and Fluid-Solid Interfaces Monday Sessions
       Session EC+SS-MoM

Paper EC+SS-MoM8
Ru Nanoparticles Prepared by Decomposition of Ru@sub3@(CO)@sub12@ on Au (111): Structural Characterization and Chemical Properties

Monday, November 4, 2002, 10:40 am, Room C-104

Session: Fuel Cells and Surface Electrochemical Reactions
Presenter: T. Cai, Brookhaven National Laboratory
Authors: T. Cai, Brookhaven National Laboratory
Z. Song, Brookhaven National Laboratory
Z. Chang, Brookhaven National Laboratory
G. Liu, Brookhaven National Laboratory
J.A. Rodriguez, Brookhaven National Laboratory
J. Hrbek, Brookhaven National Laboratory
Correspondent: Click to Email
Supported ruthenium metal particles prepared from ruthenium carbonyl have been shown as a most active catalyst for ammonia synthesis. In the emerging field of nanoscience, a goal is to make nanostructures with interesting functional properties. We have started a research program using metal carbonyls as precursors in the synthesis of nanoparticles on well-defined templates. In this study, we prepared and characterized a Au-supported Ru model catalyst under UHV by depositing metallic Ru on a Au (111) surface using triruthenium dodecacarbonyl, Ru@sub3@(CO)@sub12@, as a molecular precursor. We used the reconstructed Au (111) surface as an inert template for metallic cluster growth. Carbonyl adsorbs molecularly on the surface at 90 K and starts to dissociate at 280 K by CO elimination, as shown in TPD studies. The complete decomposition of the carbonyl occurs above 500 K, leaving metallic Ru on the surface with no significant C or O as detected by XPS. Such an atomically clean Ru deposit is also obtained on Au (111) by MOCVD of Ru@sub3@(CO)@sub12@ at an elevated substrate temperature of 550 K. The morphology of the Ru nanoparticles investigated by STM and their chemical reactivity toward simple molecules (CO, N@sub2@, NH@sub3@, O@sub2@, NO@sub2@) studied by XPS and TPD will be discussed. The research was carried out at BNL under Contract No. DE-AC02-98CH10086 with the U.S. DOE (Division of Chemical Sciences).