In-situ позитронная спектроскопия водород-индуцированных изменений дефектной структуры в композите на основе гидрида магния и металл органической каркасной структуры MIL-101

Abstract

The development of physical and chemical bases for the creation of new functional materials, including effective hydrogen storage materials, is an urgent problem of modern materials science, especially in the field of hydrogen energy. Magnesium-based alloys can accumulate up to 7.6 wt.% hydrogen [1]. However, hydrogenation of such alloys is slow and considerable temperature increase up to 573 K and higher is required [2]. The addition of MOFs can reduce the sorption and desorption temperature of the composites, which in turn reduces the desorption activation energy. MOFs particles as a result of mechanical synthesis can be distributed on the surface of larger Mg/MgH2 particles, providing some catalytic effect. The influence of milling parameters and peculiarities of evolution of the defect structure of composites during sorption-desorption has not been fully investigated, and it is agreed that changing such parameters as drum rotation speed and milling time can significantly affect the results obtained. The application of positron spectroscopy (PS) to study the intrinsic defect structure of the material as well as the evolution of composite defects in hydrogen sorption and desorption processes is becoming relevant. It is worth noting that, at the moment, positron diagnostics methods have not been used to study the interaction of hydrogen with composites based on magnesium hydride and metal-organic framework structures