Improved carbon nanotube supported Pt nanocatalysts with lyophilization

The lyophilization was used to enhance platinum (Pt) nanoparticle distribution on carbon nanotube (CNTs). The results indicate that this method is very available to uniformly disperse nanotubes and effectively prevent Pt metal particles from agglomeration. The Pt nanoparticles ranging from 2 to 5 nm in diameter are uniformly deposited on CNTs characterized by both transmission electron microscopy (TEM) and X-ray diffraction (XRD). Instead, Pt/CNT catalysts fabricated by conventional drying method present a lower dispersion degree compared with that by lyophilization. The as-prepared catalysts have higher electrochemical active surface area and higher oxygen reduction reaction (ORR) activity as compared to that by drying method characterized through cyclic voltammetry (CV) and ORR.