Synthesis method of fine-grained alpha-AlH3

Abstract

A synthesis method of fine-grained alpha-AlH3 is characterized in that ultrasonic catalytic crystallization is introduced in the crystallization stage on the basis of an ether process synthesis technology, and the energy, the strength, the frequency and other parameters of ultrasonic oscillation are controlled on the basis of guaranteeing the crystal phase purity of alpha-AlH3 to control the crystallization granularity of the alpha-AlH3 to be 10-80 [mu]m and realize controllable granularity. Ultrasonic assisted alpha-AlH3 crystallization is carried out to synthesize the fine-grained alpha-AlH3 with the purity being greater than 99%, and the frequency, the amplitude and the working mode of ultrasonic waves are adjusted to adjust the granularity in a range of 10-80 [mu]m. The method has the advantages of simple required device, easiness in realization of amplification, and realization of repeated and stable generation of granularity-controllable fine-grained high quality alpha-AlH3, and allows the total yield to be greater than 70%, the purity to be greater than 99% and the chlorine content to be lower than 0.2%.

Description

technical field [0001] The invention relates to an energetic metal hydride and a hydrogen storage material AlH 3 A fine-grained synthesis method, the AlH synthesized by this method 3 It is mainly used in solid and liquid rocket propellant high-energy additives, hydrogen storage materials, organic synthesis reducing agents and other fields. Background technique [0002] α-AlH 3 It has the characteristics of high hydrogen content (10 w.t. %) and low decomposition temperature (<100°C). Its volume hydrogen storage density is as high as 148 gH 2 / L, which is twice the volume hydrogen storage density of liquid hydrogen, and the heat required for decomposition is only 7 KJ / mol H 2 (much lower than other composite metal hydrides LiAlH 4 、LiBH 4 ), so it has potential application value in hydrogen storage materials. In addition, the α-AlH 3 Used as a fuel in solid or liquid gel propellants, its energy characteristics are significantly improved, and the specific impulse o...

AI Technical Summary

Problems solved by technology

For some fine-grained α-AlH 3 For the application, the stirring can be turned on during the synthesis process, but the effect of reducing the particle size in this way is limited, and the α-AlH formed during the crystallization process is caused by stirring 3 The edges and corners disappear, reducing the crystal quality

Too intense crystallization methods often result in poor crystal morphology, rough surface, and wide grain distribution

Another method is to increase the speed of ether through the adjustment of crystallization temperature and drop rate, and form crystal nuclei as much as possible in the crystallization process, but this method is difficult to synthesize α-AlH due to the complexity of drop rate and temperature adjustment. 3 The grain size is reduced to below 80μm