Electrochemical Characterization of 2D Pt Nanoislands

Pt nanoparticles with bi-dimensional geometry and circular shape have been synthesized and studied by in situ Fourier transform infrared spectroscopy, scanning tunneling microscopy, CO stripping voltammetry, cyclic voltammetry, and methanol oxidation in acidic and alkaline media. The experimental results suggest that Pt nanodiscs present a bi-dimensional (111) order domain on the surface and a high density of step edge sites mainly with (110) and (100) orientations. A clear correlation between the atomic surface arrangement and the catalytic activity towards the CO and methanol oxidation, as well as the voltammetric profiles in the electrolyte, was observed. Additionally, infrared spectra proved the high density of low-coordinated Pt atoms present in the nanoparticle and that CO adsorbed in linear configuration is the main adsorbate. The electrochemical study was compared with that of spherical Pt particles supported on carbon (Pt/C 20 wt.%, Etek).