Raman Spectroscopy and Electrochemical Investigations of Pt Electrocatalyst Supported on Carbon Prepared through Plasma Pyrolysis of Natural Gas

Abstract

Physicochemical and electrochemical characterisations of Pt-based electrocatalysts supported on carbon (Vulcan carbon, C1, and carbon produced by plasma pyrolysis of natural gas, C2) toward ethanol electrooxidation were investigated. The Pt 20 /C1 80 and Pt 20 /C2 80 electrocatalysts were prepared by thermal decomposition of polymeric precursors at 350°C. The electrochemical and physicochemical characterisations of the electrocatalysts were performed by means of X-ray diffraction (XRD), transmission electron microscope (TEM), Raman scattering, cyclic voltammetry, and chronoamperometry tests. The XRD results show that the Pt-based electrocatalysts present platinum metallic which is face-centered cubic structure. The results indicate that the Pt 20 /C1 80 electrocatalyst has a smaller particle size (10.1–6.9 nm) compared with the Pt 20 /C2 80 electrocatalyst; however, the Pt 20 /C2 80 particle sizes are similar (12.8–10.4 nm) and almost independent of the reflection planes, which suggests that the Pt crystallites grow with a radial shape. Raman results reveal that both Vulcan carbon and plasma carbon are graphite-like materials consisting mostly of sp 2 carbon. Cyclic voltammetry and chronoamperometry data obtained in this study indicate that the deposition of Pt on plasma carbon increases its electrocatalytic activity toward ethanol oxidation reaction.