Platinum Particles Electrochemically Deposited on Multiwalled Carbon Nanotubes for Oxygen Reduction Reaction in Acid Media

Abstract

Platinum nanoparticles supported on multiwalled carbon nanotubes (Pt/MWCNT) were prepared using controlled electrochemical deposition from Ar-saturated H2PtCl6 solution. The electrodeposition parameters were varied to observe change in the surface morphology and electrocatalytic activity of the Pt/MWCNT catalysts for oxygen reduction reaction (ORR). Surface morphology of the prepared catalysts was studied by scanning electron microscope (SEM) and scanning transmission electron microscope (STEM). For electrochemical characterization of the Pt/MWCNT electrocatalysts, CO-stripping and cyclic voltammetry (CV) experiments were performed in 0.05 M H2SO4 solution. The ORR was studied in acid medium using the rotating disk electrode (RDE) method. The results obtained were analyzed and compared to those of commercial Pt/C. The size, shape and distribution of Pt particles as well as the electrochemical behavior of Pt/MWCNT modified electrodes showed strong dependence on the deposition parameters. The catalyst materials prepared by electrochemical deposition showed higher specific activities than commercial Pt/C catalyst. The Pt/MWCNT cathode materials showed remarkable stability during repetitive potential cycling in 0.05 M H2SO4.