Ultrafine cobalt nanoparticles supported on carbon nanospheres for hydrolysis of sodium borohydride

Sodium borohydride (NaBH 4 ) is an ideal chemical carrier of hydrogen due to its high hydrogen release capacity via hydrolysis, however the reaction is restricted by a competent catalyst. Herein, we present an efficient catalyst – ultrafine non-noble Co nanoparticles supported on carbon nanospheres (CNSs) (CNSs@Co), for hydrogen generation from NaBH 4 hydrolysis in alkaline media . The ultrafine Co nanoparticles distribute evenly over the surface of the CNSs by adjusting solubility of a by-product – NaBO 2 within ethanol. The as-prepared CNSs@Co catalyst has a glorious catalytic activity for hydrogen evolution of NaBH 4 . It shows a high hydrogen generation rate (HGR) of 7447  mL H 2 . min − 1 ⋅ g M − 1 ${\text{mL}}_{{\mathrm{H}}_2}.{\min }^{-1}\cdot g_M^{-1}$ at 30 °C, and a low activation energy of 40.79 kJ mol −1 . Besides, the catalyst exhibits a stable cycling capability in a consecutive cycling test. The outstanding catalytic performance of the CNSs@Co catalyst could attribute to the ultrafine size of the Co nanoparticles (∼7 nm) and its uniform dispersion supported by the CNSs. We believe the catalyst together with its synthetic method will provide a probable strategy to promote the hydrogen generation from NaBH 4 .