A novel method for the synthesis of high-performance Pt electrocatalysts on graphitized carbon nanotubes (GCNTs) is reported. GCNTs are first noncovalently functionalized with a polyelectrolyte, poly(diallyldimethylammonium chloride) (PDDA). Pt precursors are uniformly distributed on the surface of PDDA-functionalized GCNTs via the electrostatic self-assembly between negatively charged PtCl62- and positively charged functional groups of PDDA and then Pt nanoparticles are in-situ prepared with the ethylene glycol reduction method. X-ray photoelectron spectroscopy measurement confirms the successful functionalization of PDDA on GCNTs. X-ray diffraction and transmission electron microscope images reveal that Pt nanoparticles with an average size of ~ 2.7 nm are uniformly dispersed on the PDDA-functionalzied GCNTs. Pt/GCNTs electrocatalyst exhibits two times higher activity towards oxygen reduction reaction than Pt/CNTs because of the higher Pt electrochemical surface area and the higher electrical conductivity of GCNTs. Also, Pt/GCNTs exhibit a higher stability than Pt/CNTs. This enhanced durability can be attributed to the structural integrity and higher graphitization degree of GCNTs.
Revised: March 21, 2011 |
Published: February 22, 2011
Citation
Zhang S., Y. Shao, G. Yin, and Y. Lin. 2011.Self-assembly of Pt nanoparticles on highly graphitized carbon nanotubes as an excellent oxygen-reduction catalyst.Applied Catalysis. B, Environmental 102, no. 3-4:372-377.PNNL-SA-67963.doi:10.1016/j.apcatb.2010.11.029