Chemical vapor deposition of highly dispersed Pt nanoparticles on multi-walled carbon nanotubes for use as fuel-cell electrodes

Abstract

Fuel-cell electrode catalysts with improved electrochemical properties have been prepared by dispersing Pt nanoparticles onto carbon nanotubes (CNT) using a chemical vapor deposition (CVD) method. (Trimethyl)methylcyclopentadienyl platinum (MeCpPtMe 3) has been used as a Pt precursor in the CVD process and the CVD conditions have been optimized to disperse small Pt particles onto the CNT. Pt particles synthesized by CVD have a relatively uniform size of approximately 1 nm, which is substantially smaller than in the case of a commercial Pt/carbon black catalyst (⩽4.5 nm) prepared by wet impregnation. The dispersion of Pt, estimated by CO chemisorption, is also more than 14% greater than the commercial catalyst with these smaller particles. The electrochemically active surface area (ESA), measured by cyclic voltammetry (CV), and the long-time durability of the surface area of Pt/CNT prepared by CVD are higher than those of the commercial catalyst. Consequently, the single cell performance of the former catalyst is superior to that of the latter one.