Platinum catalysts on KOH-treated multi-walled carbon nanotubes for PEM fuel cell nano sized dense structured electrodes

Abstract

In this study multi-walled carbon nanotubes (MWCNTs) were thermally treated in the presence of potassium hydroxide (KOH) at various temperatures and times and then applied as platinum (Pt) supporting materials for electrocatalysts. Pt was deposited on the MWCNTs using a colloidal method under microwave irradiation. The morphological properties of the Pt-MWCNTs were determined by transmission electron microscopy (TEM), and their electrochemical performance was evaluated using cyclic voltammetry (CV). The KOH-treated MWCNTs favored the dispersion of Pt nanoparticles with a narrow size distribution, and the Pt-MWCNT catalysts displayed excellent electrochemical performance. Notably, the electrochemical surface areas (ECSA) of the Pt-MWCNTs were higher than those of acid-treated Pt-MWCNTs. Moreover, the KOH-treated Pt-MWCNTs were more durable (measured in terms of CV performance) than the acid-treated Pt-MWCNTs. Thus, heat activation with KOH is an effective means of modifying MWCNT surfaces for use as Pt supporting materials with higher ECSA, making them suitable for use as electrocatalytic materials in proton exchange membrane fuel cells.