The stabilization of supported Au nanoparticles in a highly sintering environment using high surface free energy Pt and Ru cores

Abstract

To stabilize carbon supported gold nanoparticles which sinter rapidly in a highly corrosive chemical environment containing gaseous HCl at elevated temperature (180 °C), bimetallic Ru@Au and Pt@Au core–shell supported nanoparticles were prepared by anchoring shells of Au onto higher surface free energy cores of Pt and Ru. Highly dispersed (sub-2 nm) Pt and Ru particles prepared by electrostatic adsorption of the respective precursors onto the carbon support were themselves stable in the corrosive medium. As confirmed by XRD, chemisorption, and HRTEM analyses of the fresh and treated nanoparticles, Au shells deposited onto the Pt and Ru metal cores were completely stabilized against sintering and in fact appeared to spread on the high surface free energy metal core surfaces during the treatments. High surface free energy core anchoring of less stable metal shells appears to be a valid strategy extendable to many other systems.