Nanocomposites and nanomaterials
Hydrogen production through catalytic hydrolysis of borohydrides
S.M. Lesik, I.M. Ivanenko
Department of Inorganic Substances Technology, Water Treatment and General Chemical Engineering, National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute", Ukraine, Kyiv, 03056, 37 pr. Pеremohy, 4 building, luckystrike191012@gmail.com

The invention of internal combustion engines shows that traditional sources of energy from fossil fuels are unviable in the long run because they have obvious limitations due to raw materials. At the same time, the rate of use of fossil resources is thousands of times higher than the rate of formation of new ones. One of the advanced systems for obtaining energy from alternative raw materials is systems that use hydrogen as an energy source. The use of hydrogen as an energy resource was first published in an article in 1972 [1]. Already today, several automakers produce hydrogen cars, namely: Honda, Toyota, Hyundai, etc. [2]. Since the energy density of hydrogen is one of the highest, it is 1.4∙108 J/kg, hydrogen cannot be a source of energy for portable devices such as mobile phones and laptops, but can meet the needs of industry [3].
The key problem of storing and transporting hydrogen due to explosiveness can be solved in several ways, one of which is the use of sodium borohydride with its subsequent hydrolysis. NaBH4 is a non-combustible and environmentally friendly compound in both dry and dissolved states, with a high ratio of energy density to mass, which is an excellent material for storing hydrogen, the content of which is ~ 10.8% of the mass. The hydrolysis reaction of sodium borohydride is a liquid-phase catalytic heterogeneous process with heat release, and the decomposition product, sodium metaborate, can be used further as hydrogen storage. According to the literature [4], the rate of decomposition of sodium borohydride is virtually independent of rising temperatures above 40°C, and complete decomposition occurs within about an hour. It is essential that the decomposition rate can be significantly adjusted using a suitable catalyst. It should be noted that currently there are two methods of industrial production of sodium borohydride, which increase the prospects for the use of this carrier: the Brown-Schlesinger process (sodium hydride reaction with trimethylborate) [5] and the Bayer process (borosilicate glass reaction with sodium and hydrogen) [6].

1.	Bockris J.O., Appleby A.J. The hydrogen economy – an ultimate economy // Environ This Mon.-1972.-3.-P. 29-35.
2.	Bertel S. Hydrogen vehicle // Wikiwand.-2021. https://www.wikiwand.com/en/Hydrogen vehicle
3.	Chengguang L., Yi.J., Xiangdong Y. Recent advances in liquid-phase chemical hydrogen storage // En Storage Mat.-2020.-26.-P. 290-312.
4.	Rohendi D., Syarif N., Wati E.K. Storage and Release of Hydrogen as a Fuel of the Fuel Cell with Media of NaBO2/NaBH4 // Earth Environ Sci.-2019.-248.
5.	Schlesinger H. I., Herbert C. B., Abraham B., Bond A. C., Norman D., Finholt A. E., James R. G., Henry H., Leo H., Earl K. H., Katz J. J., Knight J., Lad R. A., Darwin L. Mayfield, Louis R., Ritter D. M., Anthony M. S., Irving Sheft, Tuck L. D., Walker A. O. New Developments in the Chemistry of Diborane and the Borohydrides // J Am Chem Soc.-1953.-75.-P. 186-190.
6.	Xia Z. T., Chan S. H. Feasibility study of hydrogen generation from sodium borohydride solution for micro fuel cell applications // J Pow Sources.-2005.-152.-P. 46-49.