Physico-Chemical nanomaterials science

Hydrogen production through hydrolysis of sodium borohydride
Ruda A.O., Ivanenko I.M., Burmak A.P.
National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute". Prospect Pеremohy, 37, 4 building, Kyiv-03056, Ukraine. 
E-mail: irinaivanenko@hotmail.com

Sodium borohydride is stable in dry air, and is easily handled like common chemicals compared with other hydrogen storage materials. Generating H2 catalytically from NaBH4 solutions has many advantages: NaBH4 solutions are nonflammable; reaction products are environment tally benign; rate of H2 generation is easily controlled; the reaction product NaBO2 can be recycled; H2 can be generated even at low temperatures. The theoretical hydrogen amount released is 10,8 wt.% by NaBH4 hydrolysis reaction and half of hydrogen is from H2O. Furthermore, the gravimetric capacity of NaBH4 is higher than that of metal hydrides and the volumetric capacity of NaBH4 is higher than that of compressed and liquefied hydrogen. Due to these merits mentioned above, hydrogen generation from NaBH4 hydrolysis has attracted many attentions [1]. 
Though the hydrolysis of NaBH4 at room temperature is spontaneous, the hydrogen generation rate is quite low and will decrease as there action proceeds due to an increase of pH value of the solution caused by the formation of borates. Therefore, the utilization of catalyst is indispensable in order to accelerate the hydrolysis reaction [2].
Different catalysts such as ruthenium (Ru), cobalt (Co) supported catalyst, nickel (Ni) based catalyst, Co-Ni catalyst, Ni-B catalyst, Ni-CoB catalyst, copper Cu-Co catalyst, rhodium (Rh), platinum (Pt), Pt-Ru, Co-B/Pd-Pd, Pt-Ru, Pt-Pd alloys etc. have been extensively studied. However, due to the high price of noble metal catalysts, there is the need to develop alternative catalysts based on cheaper transition metals [3].

1.	Liu B.H., Li Z.P. A review: Hydrogen generation from borohydride hydrolysis reaction // J Power Sources.-2009.-Vol.187.-P.527-534.
2.	Li H., Liao J., Zhang X., Liao W., Wen L., Yang J., Wang H., Wang R. Controlled synthesis of nanostructured Co film catalysts with high performance for hydrogen generation from sodium borohydride solution // J Power Sources.-2013.-Vol.239.-P.277-283.
3.	Sahin O, Kılınç D, Saka C. Hydrogen generation from hydrolysis of sodium borohydride with a novel palladium metal complex catalyst // J Energy Institute.-2016.-Vol. 89.-№2.-P.182-189.