Synthesis of novel hollow graphitic vesicle-supported Pt nanoparticles for oxygen reduction reaction

Abstract

A new type of interconnected hollow graphitic vesicle (HGV-T) with high purity was successfully synthesized by pyrolysis of cyclohexane over Co3O4 nanoparticles. Heat treatment was proven to be an effective way to make the shell permeable, thus allowing to easily remove metal core by facile acid leaching at room temperature. The overall transition process was investigated in detail on the basis of the structures of formed carbons and the crystal changes of cobalt species at different reaction stages. It was found that the wall thickness of HGV-T could be tailored by varying the deposition time, and the graphitization degree of HGV-T was highly dependent on the annealing temperature. Upon support of Pt, HGV-T shows much higher electrocatalytic activity and durability than commercial Pt/C catalyst in the oxygen reduction reaction as results of its open hollow network, high dispersion of Pt, excellent electrical conductivity and high corrosion resistance. The electrocatalytic activity of Pt/HGV-700 is 2.7 times as high as that of commercial Pt/C under the same testing conditions, which endows it with a potential for serving as an alternative support of fuel cell.