Transition metal-N/C composite magnesium-based hydrogen storage material and preparation method thereof

Abstract

The invention relates to a transition metal-N / C composite magnesium-based hydrogen storage material and a preparation method thereof, belonging to the technical field of hydrogen storage materials. The main component of the hydrogen storage material is magnesium, and the hydrogen storage material is prepared by synergistic catalysis of rare earth, transition metal nitrate and a nitrogenous polyvinylpyrrolidone polymer, and has a nanocrystalline structure and excellent low-temperature hydrogen absorption and desorption dynamic performance. The preparation method of the hydrogen storage material comprises the following steps: preparing a magnesium-rare earth as-cast hydrogen storage alloy, preparing a transition metal-N / C composite material, compounding the magnesium-rare earth as-cast hydrogen storage alloy and the transition metal-N / C composite material by using a mechanical ball milling method, performing cooling, and carrying out low-temperature passivation to obtain the transition metal-N / C composite magnesium-based hydrogen storage material. According to the invention, rare earth elements are added into magnesium, the reversible hydrogen storage characteristic of the magnesium is greatly improved through the synergistic catalysis effect of the rare earth elements, carbon, nitrogen and transition metal, the wall sticking phenomenon in a mechanical ball milling process is overcome, the recovery rate of the material is increased, and the high-capacity magnesium-based composite hydrogen storage material with the excellent low-temperature hydrogen absorption performance is obtained.

Description

technical field [0001] The invention belongs to the technical field of hydrogen storage materials, and in particular relates to a transition metal-N / C composite magnesium-based hydrogen storage material and a preparation method thereof. Background technique [0002] Hydrogen energy has been extensively studied as a clean, efficient, and safe new energy source, but how to store hydrogen energy safely and efficiently is still a key issue in hydrogen energy applications, compared with traditional gaseous hydrogen storage and liquid hydrogen storage , The solid hydrogen storage material can not only store hydrogen effectively, but also avoid the consumption, leakage and safety problems of hydrogen gas during use. However, among numerous solid-state hydrogen storage materials, only light metals such as Mg can have a high hydrogen storage specific gravity, which is very important for the development of hydrogen storage functional systems that can cover an actual mileage greater th...

AI Technical Summary

Problems solved by technology

However, magnesium-based hydrogen storage alloys have a certain degree of toughness and ductility, which makes them easy to adhere to the grinding balls and tank walls when they are treated by ball milling, making them in fact unable to withstand sufficient ball milling.

More importantly, its cold welding rate is much greater than its fracture rate, making it difficult to refine the alloy, requiring higher energy and power to refine it

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