The synthesis procedure of the hollow carbon hemispheres (HCHs) using glucose as carbon source and polystyrene spheres (PSs) as templates and the formation mechanism of the HCHs have been presented. The HCHs have regular morphology and high BET surface area of 702.7 m(2) g(-1). The advantage of the HCHs compared to the hollow carbon spheres is that the HCHs can provide similar surface area at reduced volume. The electrocatalytic activity of ethanol oxidation on Pd supported on HCHs electrocatalyst (Pd/HCH) is 2.8 times higher than that of Pd supported on commercial Vulcan XC-72 carbon (Pd/C) electrocatalyst at the same Pd loadings. The high surface area is beneficial for the dispersion of the precious metal nanoparticles to increase their utilization. The hemispherical structure with hollow shell results in the improvement in the mass transfer and therefore more concentrated ethanol solution can be used to increase the energy density. (C) 2010 Elsevier B.V. All rights reserved.