CoO nanocrystals as a highly active catalyst for the generation of hydrogen from hydrolysis of sodium borohydride

• Published in: Journal of power sources Vol. 220; pp. 391 - 398
• Main Authors: Lu, Aolin, Chen, Yuanzhi, Jin, Jiarui, Yue, Guang-Hui, Peng, Dong-Liang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.12.2012; Elsevier
• Subjects: Alternative fuels. Production and utilization; Applied sciences; Catalysis; Catalyst; Catalytic reactions; Chemistry; Cobalt(II) oxide; Energy; Exact sciences and technology; Fuels; General and physical chemistry; Hydrogen; Hydrogen generation; Hydrolysis; Sodium borohydride; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Hydrolysis; Hydrogen generation; Sodium borohydride; Cobalt(II) oxide; Catalyst; Performance evaluation; Cobalt oxide; Crystalline phase; Catalytic reaction; Cubic crystals; Spherical shape; Basic solution; Hydrogen; Transition metal; Acetate; Cobalt; Hydroborates; Noble metal; Sodium Hydroborates; Comparative study; Nanocrystal; Hydrogen production
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2012.08.010

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 H2 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 H2 generation from the hydrolysis of borohydrides. [Display omitted] ▸ A new catalyst for the generation of H2 from hydrolysis of NaBH4 has been found. ▸ Octahedral and near-spherical CoO nanocrystals exhibit excellent catalytic property. ▸ A maximum H2 generation rate of 8333 ml min−1 g−1 has been obtained at 303 K. ▸ Exposed crystal facets make differences to the catalytic behavior. ▸ CoO nanocrystals can be a promising candidate for substituting noble metal catalyst.