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氨合硼氢化钛是一类放氢温度适宜的高容量储氢材料,但已报道的通过球磨法制备的氨合硼氢化钛通常含有质量分数42%以上的LiCl杂质,降低了体系总含氢量的同时也为氨合硼氢化钛本征放氢性能的表征带来了困难.因此,纯氨合硼氢化钛的制备和性能表征十分必要.本文以钛酸四异丙酯、乙硼烷、四氢呋喃和NH_3为初始原料,通过先制备前驱体Ti(BH_4)_3·2THF,然后再氨化的二步反应首次成功合成纯Ti(BH_4)_3·5NH_3,并对前驱体和氨合硼氢化钛的组成、结构和放氢性能进行系统地研究.结果表明,前驱体Ti(BH_4)_3·2THF属于斜方晶系,Pbcn空间群,且在室温下能稳定存在,是制备氨合硼氢化钛的良好前驱体;纯Ti(BH_4)_3·5NH_3具有良好的放氢性能,于75℃开始放氢,至200℃释放质量分数约10%的氢气.
Ammonium borohydride is a type of high-capacity hydrogen storage material suitable for hydrogen desorption temperature. However, it has been reported that ammoniacal titanium borohydride prepared by ball milling usually contains more than 42% by mass of LiCl impurities, reducing the total hydrogen content of the system But also brings difficulties for the characterization of the intrinsic hydrogen desorption performance of Ammonium borohydride.Therefore, it is necessary to prepare and characterize the pure Ammonia borohydride.By using tetraisopropyl titanate, diborane , THF and NH_3 as initial materials, the pure Ti (BH_4) _3 · 5NH_3 was synthesized for the first time through the first step of preparing the precursor Ti (BH_4) _3 · 2THF and then re-ammoniating. The results show that the precursor Ti (BH_4) _3 · 2THF belongs to orthorhombic and Pbcn space group and can exist stably at room temperature, Titanium good precursor; pure Ti (BH_4) _3 · 5NH_3 has good hydrogen desorption performance, at 75 ° C start releasing hydrogen to 200 ° C mass fraction release of about 10% of hydrogen.