Hollow PtCo nanosphere electrocatalyst-supported multi-walled carbon nanotubes (MWCNTs) were prepared at room temperature in a homogeneous solution employing cobalt metal nanoparticles as sacrificial templates. The structure and elemental composition of the resulting hollow PtCo/MWCNT composites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). The hollow PtCo/MWCNT electrocatalysts demonstrated enhanced electrocatalytic activity toward methanol oxidation compared with carbon nanotube-supported solid PtCo nanoparticles and commercial E-TEK Pt/C (20 wt.% Pt) catalysts. (C) 2009 Elsevier Inc. All rights reserved.