Magnesium hydride hydrogen storage material based on graded porous microspheres Ti-Nb-O and preparation method thereof

Abstract

The invention discloses a magnesium hydride hydrogen storage material based on graded porous microspheres Ti-Nb-O. The magnesium hydride hydrogen storage material is prepared by mixing and mechanically ball-milling magnesium hydride and graded porous microspheres Ti-Nb-O, the graded porous microspheres Ti-Nb-O are prepared by a solvothermal method and a calcining method; the diameter is 1-2 [mu] m, the microstructure is spherical, the specific surface area is 27.63 m < 2 > / g, and the pore size distribution is 38-40 nm. The preparation method comprises the following steps: 1, preparing a hierarchical porous microsphere Ti-Nb-O precursor; 2, preparation of a graded porous microsphere Ti-Nb-O; and 3, preparing the magnesium hydride hydrogen storage material based on the graded porous microspheres Ti-Nb-O. As the application in the field of hydrogen storage, the initial hydrogen desorption temperature of the system is reduced to 189 DEG C, and the hydrogen desorption amount reaches 6.96 wt%; the isothermal complete hydrogen desorption temperature is 300 DEG C, and the hydrogen desorption amount within 60 min reaches 6.82 wt%; and under the condition that the isothermal hydrogen absorption temperature is 50 DEG C, 1.78 wt% of hydrogen is absorbed within 60 min. The activation energy of catalytic hydrogen desorption is Ea (des) = 92.7 kJ / mol, and the activation energy of catalytic hydrogen absorption is Ea (abs) = 26.0 kJ / mol; the desorption reaction enthalpy change Hd is equal to 69.6 kJ / mol. And the cycle retention rate is 92.3%.

Description

technical field [0001] The invention relates to the technical field of hydrogen storage materials of new energy materials, in particular to a magnesium hydride hydrogen storage material based on hierarchical porous microspheres Ti-Nb-O and a preparation method thereof. Background technique [0002] Traditional fossil energy such as oil and coal are increasingly exhausted with the continuous use of human beings. The resulting energy crisis restricts the development of human society. It has become the consensus of all mankind to find green, efficient and renewable new energy to replace fossil energy. A lot of research results have been obtained. Hydrogen energy has the advantages of abundant raw material sources, high energy density, environmentally friendly products, and renewable energy. It has become one of the most potential alternative energy sources at present. At present, the development and utilization of hydrogen energy is mainly faced with three key problems: produc...

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Problems solved by technology

[0017] 1. The catalyst carrier does not have good catalytic performance;

[0018] 2. The catalyst does not have the characteristics of both the carrier and the load;

[0019] 3. The catalyst has catalytic performance, but has no special shape. The special shape of the catalyst has a strong influence on MgH 2 The role of hydrogen storage performance;

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