TY - JOUR AU - Ershova, О. AU - Dobrovolsky, V. AU - Solonin, Yu. AU - Koval, О. PY - 2020/12/27 Y2 - 2024/03/29 TI - THE EFFECT OF Fe AND Y ON THE HYDROGEN SORPTION PROPERTIES, THERMAL STABILITY, AND KINETICS OF HYDROGEN DESORPTION FROM THE MgH2 HYDRIDE PHASE OF A MECHANICAL ALLOY Mg + 10%wt.Fe + 5%wt.Y JF - Vidnovluvana energetika JA - VE VL - IS - 4(63) SE - Complex Problems of Power Systems Based on Renewable Energy Sources DO - 10.36296/1819-8058.2020.4(63).31-41 UR - https://ve.org.ua/index.php/journal/article/view/276 SP - 31-41 AB - An effective and safe way to store hydrogen is to chemically bind it to metal hydrides. Despite much attention of scientist spaid to magnesium hydride, it has not found wide applications as a hydrogen material-accumulator for automotive industry because of the difficulty of two major drawbacks: high temperature (300 0C at 0,1 MPa H2) and its slow dissociation kinetics. In this work, with the aim of lowering the temperature, improvement the kinetics of the decomposition of stoichiometric MgH2 hydride the possibility of its complex doping by Fe and Y using the method of reactive mechanochemical alloying (RMA)has been investigated. Mechanical alloys Mg + 10 % wt. Fe + 5 % wt. Y (MA1) and Mg + 10 % wt. Fe (MA2) have been synthesized and its phase composition, microstructure, hydrogen-sorption properties, thermal stability and hydrogen desorption kinetics have been investigated employing the X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermodesorption spectroscopy (TDS) methods. To evaluate the influence of complex alloying on decomposition temperature and thermal stability of MgH2 phase hydrogen desorption isobars have been obtained at the first heating after RМA synthesis of МA samples and after the next cyclic hydrogenation from gas phase. All isobars were obtained at hydrogen pressure in the reactor 0.1MPa and sample heating rate of 3o/min. They were used to determine both the hydrogen desorption beginning temperature (Тbeg.) from hydride phase MgH2 of МAs and temperature Tmax, that corresponds to the maximum speed of hydrogen release. The kinetic curves of hydrogen desorption from mechanical alloys-composites have been obtained at the constant hydrogen pressure of 0.1 MPa in the reactor and temperature 310 and 330 0C. They were used to determine both the hydrogen time release of half of hydrogen quantity (τ1/2) and total hydrogen quantity release (τt) from MAs. It has been established that the addition of Fe and Y to magnesium leads to significant improvement in the kinetics of hydrogen desorption from the  hydride phase MgH2, which is evidenced by a significant reduction (in 15 and 6 times) in the time of release of half and all hydrogen from it at 330 0C. The developed materials allow their practical use at stationary application conditions.Ref.48, table 2, figures 9. ER -