Hydrogen Storage Properties of Ball Milled MgH2 with Additives- Ni, V and Activated Carbons Obtained from Different By-Products

Eli Grigorova; Pavel Markov; Boyko Tsyntsarski; Peter Tzvetkov; Ivanka Stoycheva

doi:10.3390/ma16206823

Hydrogen Storage Properties of Ball Milled MgH₂ with Additives- Ni, V and Activated Carbons Obtained from Different By-Products

Materials (Basel). 2023 Oct 23;16(20):6823. doi: 10.3390/ma16206823.

Authors

Eli Grigorova¹, Pavel Markov¹, Boyko Tsyntsarski², Peter Tzvetkov¹, Ivanka Stoycheva²

Affiliations

¹ Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bld. 11, 1113 Sofia, Bulgaria.
² Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bld. 9, 1113 Sofia, Bulgaria.

Abstract

The hydrogen sorption of materials based on 80 wt.% MgH₂ with the addition of 15 wt.% Ni or V and 5 wt.% activated carbons synthesized from polyolefin wax, a waste product from polyethylene production (POW), walnut shells (CAN), and peach stones (CPS) prepared by milling under an inert Ar atmosphere for a period of 1 h, is investigated. All precursors are submitted to pyrolysis followed by steam activation in order to obtain the activated carbons. The hydrogen sorption evaluations are carried out for absorption at 473 and 573 K with pressure of 1 MPa and for desorption at 623 and 573 K with pressure of 0.15 MPa. The composition of the samples after milling and hydrogenation is monitored by X-ray diffraction analyses. The 80 wt.% MgH₂-15 wt. %Ni-5 wt.% POW or CAN after absorption-desorption cycling and in a hydrogenated state at 573 K and 1 MPa are analyzed by TEM.

Keywords: carbon materials; hydrogen storage; metal hydrides; sorption.

Grants and funding

This research was funded by the National Science Fund of the Bulgarian Ministry of Education and Science (Project N° DFNI-KП-06-H27/9, 8 December 2018). Some of the experiments were carried out using the equipment from the National Infrastructure SI ESHER, which is supported by the Bulgarian Ministry of Education and Science under grant agreement N° DO1-161/28.07.22. The “European Network on Materials for Clean Technologies” TwinTeam project N° DO1-272 gave the authors the chance to discuss their results at the SizeMat4 conference and provided financial support for the publication.