Stabilization and Characterization of Pt Nanoparticles on HOPG

Abstract

Platinum nano-catalysts are deposited, either by electrodeposition at constant potential or thermal decomposition, onto highly ordered pyrolytic graphite (HOPG). To help stabilize the nano-catalyst, the HOPG substrate is oxidized either by electrochemical methods or by ozone gas. The combination of two deposition techniques and two substrate oxidation techniques results in four different types of samples. As a point of reference, the particle morphology, activity towards oxidation of adsorbed carbon monoxide, and electrochemical stability of the four different types of samples are compared to a sample made by electrodeposition of Pt onto freshly cleaved HOPG. Of the four samples prepared, the combination of thermal reduction onto ozone oxidized HOPG was found to produce the most stable platinum nano-catalyst.