Fabrication of ball-milled MgO–Mg(OH)2-hydromagnesite composites and evaluation as an air-stable hydrogen storage material

• DOI: 10.1016/j.ijhydene.2020.03.020
• Publication Date: 2020-03-27T05:41:53Z
• Authors: A. Martinez-Garcia; A.K. Navarro-Mtz; E. Reguera; M. Valera-Zaragoza; J.A. Morales-Serna; E.A. Juarez-Arellano
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract A phase stability map of metallic magnesium powder, exposed to environmental conditions for 12 months (Mg-12M) and subjected to different high-energy ball-milling speeds and milling times, was constructed. Mg-12M−160 [½MgO-⅓Mg(OH)2-⅙hydromagnesite] and Mg-12M−640 [¼MgO-⅝Mg(OH)2-⅛hydromagnesite] composites were obtained changing the milling conditions. The correlation among the accumulated energy (ΔEaccum), the impact energy (ΔEhit), and the phase stability under different high-energy ball-milling conditions were generated. The Mg-12M−160 composite had a hydrogen storage capacity of 0.63 wt% at −196 °C and 8.3 bar, although further hydrogen adsorption at higher pressures is expected. Structural defects play a significant role in the adsorption capacity. A representation of the possible absorption mechanism is proposed.