HYDROGEN SORPTION IN ORDERED Mg-In ALLOYS

conference paper

English

Hydrogen storage (HS) performance of three Mg- xIn-yCB alloys (CB - amorphous carbon, x = 55, 64, 73; y = 10 wt%) was studied. Indium concentration covered an area of ordered beta structures. Alloys were prepared by ball-milling in hydrogen atmosphere. Kinetic curves and PCT isotherms were measured in the temperature interval from 200 degrees C to 325 degrees C. X-ray diffraction spectroscopy ( XRD) was used for structure investigation. Alloy with x = 73 wt% In (beta '' structure) showed reversible amorphization during temperature cycling between about 100 degrees C and 350 degrees C. Hydrogen sorption experiments were done by the Sieverts method under the hydrogen gas pressure ranging from 0.1 MPa to 2.5 MPa. It was found that hydrogen sorption capacity varied between 0.47 and 1.1 wt% H-2. Hydride formation enthalpy Delta H calculated from desorption PCT experiments was significantly lower than Delta H, known for pure Mg. This invoked an idea that atomic order of Mg-based HS materials might decrease the high thermodynamic stability of hydride phase.

Hydrogen storage; Mg alloys; hydride stability; ordering

ČERMÁK, J.; KRÁL, L.; ROUPCOVÁ, P.

22. 5. 2019

978-80-87294-92-5

28TH INTERNATIONAL CONFERENCE ON METALLURGY AND MATERIALS (METAL 2019)

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