Abstract
This study focused on electrochemically and visually characterizing tin (Sn), platinum (Pt) and rhodium (Rh) nanoparticles on platinum sputtered mica electrodes by means of Scanning Tunneling Microscopy (STM) and Scanning Tunneling Spectroscopy (STS). The purpose of this study was to analyze the correlation between the distribution of tin on platinum and rhodium electrode surfaces and the electrochemical activity of these surfaces toward ethanol oxidation. Pt, Rh, and Sn nanoparticles were synthesized, purified, cleaned and deposited in different combinations on Pt coated mica electrodes to create a surface made up entirely of nanoparticles. Then the electrochemical behaviors of the modified Pt electrodes were found through cyclic voltammetry. The surface nanostructure was characterized using STM and composition through STS. Together composition, surface structure and electrochemistry yield a thorough characterization of the modified electrodes, which can be studied to optimize Pt ethanol fuel cell catalysts. Two of the electrodes studied, consisting of nanoparticle deposits (nominal compositions Pt2Sn and Rh2Sn), showed higher current peaks at low potentials in the CV scans compared to pure Pt and Rh electrodes. These electrodes also showed a homogenous distribution of the different types of nanoparticles.
