Liu, Y. S.Y. S.LiuRay, K. G.K. G.RayJørgensen, M.M.JørgensenMattox, T. M.T. M.MattoxCowgill, D. F.D. F.CowgillEshelman, H. V.H. V.EshelmanSawvel, A. M.A. M.SawvelSnider, J. L.J. L.SniderYork, W.W.YorkWijeratne, P.P.WijeratnePham, A. L.A. L.PhamGunda, H.H.GundaLi, S.S.LiHeo, T. W.T. W.HeoKang, S.S.KangJensen, T. R.T. R.JensenStavila, V.V.StavilaWood, B. C.B. C.WoodKlebanoff, L. E.L. E.Klebanoff2025-05-032025-05-032020-10-011932745510.1021/acs.jpcc.0c051422-s2.0-85095596737https://d8.irins.org/handle/IITG2025/13793Metal borides have attracted the attention of researchers due to their useful physical properties and unique ability to form high hydrogen-capacity metal borohydrides. We demonstrate improved hydrogen storage properties of a nanoscale Mg-B material made by surfactant ball milling MgB2 in a mixture of heptane, oleic acid, and oleylamine. Transmission electron microscopy data show that Mg-B nanoplatelets are produced with sizes ranging from 5 to 50 nm, which agglomerate upon ethanol washing to produce an agglomerated nanoscale Mg-B material of micron-sized particles with some surfactant still remaining. X-ray diffraction measurements reveal a two-component material where 32% of the solid is a strained crystalline solid maintaining the hexagonal structure with the remainder being amorphous. Fourier transform infrared shows that the oleate binds in a "bridge-bonding"fashion preferentially to magnesium rather than boron, which is confirmed by density functional theory calculations. The Mg-B nanoscale material is deficient in boron relative to bulk MgB2 with a Mg-B ratio of ∼1:0.75. The nanoscale MgB0.75 material has a disrupted B-B ring network as indicated by X-ray absorption measurements. Hydrogenation experiments at 700 bar and 280 °C show that it partially hydrogenates at temperatures 100 °C below the threshold for bulk MgB2 hydrogenation. In addition, upon heating to 200 °C, the H-H bond-breaking ability increases ∼10-fold according to hydrogen-deuterium exchange experiments due to desorption of oleate at the surface. This behavior would make the nanoscale Mg-B material useful as an additive where rapid H-H bond breaking is needed.falseJournalhttps://www.osti.gov/biblio/1670751https://v2.sherpa.ac.uk/id/publication/779921761-217711 October 202023arArticle23