固相真空转晶法制备α-AlH_3及其稳定化

Preparation of α-AlH_3 via solid-state and vacuum crystal transformation method and its stabilization

AlH_3由于其极高氢含量和潜在的应用价值而得到了国内外广泛的关注,然而,现有的α-AlH_3制备工艺复杂、成本高及长期稳定性能差等问题,而限制了其广泛研究与应用。采用固态真空转晶法制备晶型单一、高品质的α-AlH_3。而后采用小分子化合物对α-AlH_3进行包覆实验,并通过X射线衍射、电子顺磁共振仪、热失重差热分析、扫描电子显微镜和透射电子显微镜证实包覆成功。对包覆前后的α-AlH_3在室温和90%湿度条件下进行稳定性对比实验,结果表明,未包覆的α-AlH_3在10 d后即分解,而包覆后的α-AlH_3在16 d后仍保持很好的稳定性。该技术摒弃高毒甲苯溶液转晶行为,兼具成本低和连续化工业生产的优点,为α-AlH_3的规模化生产和长期贮存提供了新的思路。

Aluminum hydride is particularly attractive as a hydrogen storage material due to its high hydrogen volumetric capacities.However,issues of complicated preparation process,poor stability and high cost of α-AlH3 restrict its further development and applications.Herein,high-quality α-AlH3 has been prepared based on a solid-state crystal transformation method under vacuum condition.It has been successfully coated,which was confirmed by a combined analysis of XRD,EPR,TGA-DSC,SEM and TEM.In the condition of room temperature and 90% humidity,the pristine α-AlH3 decomposed 10 days later,whereas the coated α-AlH3 shows good stability even after 16 days storage.This technique excludes the traditional crystallization transformation behavior of AlH3 in toxic toluene,providing a new idea way of large-scale production of the α-AlH3 with long-term storage capability.