Method for preparing nanometer limited range magnesium-based hydrogen storage material

Abstract

The invention discloses a method for preparing a nanometer limited range magnesium-based hydrogen storage material. The nanometer limited range method belongs to the technical field of new energy materials. The method is characterized in that the hydrogen storage material is formed by loading magnesium hydride (MgH2) in nanopores of a mesoporous framework material. The method comprises the following steps: dipping dibutyl magnesium (MgBu2) and a mesoporous framework material, replacing MgBu2 with MgH2 loaded inside and outside the nanopores of the mesoporous framework material in a high-pressure reactor under high temperature and high pressure, washing MgH2 loaded outside the pores away by using pentane, drying, thereby obtaining the material. The nanometer limited range magnesium-based hydrogen storage material prepared by the method can release hydrogen at room temperature and has excellent properties in hydrogen absorption and desorption kinetics and hydrogen desorption thermodynamics. The method disclosed by the invention is easy to operate and high in synthesis speed and the prepared material is high in dispersity; therefore, the method has ideal application prospects.

Description

technical field [0001] The invention confines the hydrogen storage material in the nanopore through the mesoporous framework material, and belongs to the technical field of clean energy materials. Background technique [0002] Energy shortage and environmental pollution have become the most serious problems facing the world today, and the development of clean energy and renewable energy is imminent. Especially in recent years, the impact of "smog" on people's lives and the threat to life safety have been increasing. It can be seen that the search for new clean energy is of great significance to the sustainable development of the whole world and our country. Hydrogen is an ideal low-pollution or zero-pollution clean energy. Although the development of hydrogen-fueled vehicles is difficult, as a long-term goal, it will eventually be one of the most important ways to solve urban air pollution. The newly revised hydrogen storage standard of the US Department of Energy (DOE) is:...

AI Technical Summary

Problems solved by technology

Various hydrogen storage systems such as metal hydrides, carbon materials, mesoporous materials, composite hydrides, and chemical hydrides currently studied cannot meet the requirements of on-board hydrogen sources.

The practical problem is: a hydrogen storage system with a high hydrogen content has a high hydrogen absorption and desorption temperature and poor hydrogen absorption and desorption kinetics, while a material with a low hydrogen desorption temperature and a high kinetic hydrogen absorption and desorption rate has a low hydrogen storage capacity

However, since magnesium hydride (MgH 2 ) The hydrogen release temperature is close to 573K at 1 atmospheric pressure (ΔH=75kJ mol -1 h 2 ), and the kinetic hydrogen absorption and desorption rate is extremely slow, so there is still a long way to go to meet the requirements of vehicle-mounted hydrogen sources

[0003] At present, the methods to improve the hydrogen absorption and desorption performance of Mg mainly include doping catalysis and nanocrystallization. However, these two methods greatly increase the kinetic rate of hydrogen absorption and desorption of Mg, and even realize the hydrogen absorption and desorption of Mg at room temperature. But none of them changed the thermodynamics of hydrogen desorption, that is to say, the dehydrogenation temperature is still maintained above 523K

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