We report the excellent catalytic performance of CoO nanocrystals on the catalytic hydrolysis of alkaline NaBH4 solutions. COO nanocrystals with octahedral and near-spherical shapes are synthesized using a facile chemical solution method that employed cobalt acetate tetrahydrate as metal precursor in the presence of oleylamine. The octahedral CoO nanocrystals typically have a size of 40-50 nm, while the near-spherical nanocrystals have a size varying from 8 to 13 nm. Both of them have a face centered cubic (fcc) crystalline phase. Catalytic tests show that the as-synthesized CoO nanocrystals exhibit very high activities for the H-2 generation from the hydrolysis of alkaline NaBH4 solutions. The maximum hydrogen generation rate of the as-synthesized CoO nanocrystals exceeds most reported values of transition metal or noble metal contained catalysts performed in alkaline NaBH4 solutions. The influences of shape on the catalytic behaviors of as-synthesized COO nanocrystals are also compared and analyzed. The results presented in this study indicate that CoO nanocrystals are a promising candidate to replace noble metal catalysts in the H-2 generation from the hydrolysis of borohydrides. (C) 2012 Elsevier B.V. All rights reserved.