高活性Al-LiBH_4-Bi铝基复合制氢材料

High active Al-LiBH_4-Bi composite for hydrogen generation

采用机械球磨法制备高活性的铝基复合制氢材料,以Al-5%Li BH4为研究对象,采用Bi部分取代Al制备了Al-5%Li BH4-Bi三元体系。并且讨论了球磨时间、球料比、球磨速度分别对Al-5%Li BH4-3%Bi复合材料的产氢性能的影响。结果表明,球料比为30∶1、球磨速度为500 r/min球磨3.5 h的复合材料的产氢量最高为1 480 m L/g,最大产氢速率较低为975 m L/(g·min)。若降低球料比20∶1、球磨速度400 r/min、球磨时间2 h,可大幅提高材料的最大产氢速率,但会降低材料的氢气产量。采用X射线衍射(XRD)仪和扫描电镜(SEM)对所得铝基复合材料进行物相分析和形貌分析,结果表明,在球磨过程中,Al、Li BH4、Bi三者只是机械混合,没有形成新相。

A high active Al-base composites for fast hydrogen generation in pure water was prepared by ball milling. The Bi additive was added into the AI-5% LiBH4 composite system for preparing Al-5% LiBH4-Bi. The effects of milling time, ball material ratio and milling rate on the performance of hydrogen generation by the reaction of AI-5% LiBH4-3% Bi with pure water were studied. For Al-5% LiBH4-3% Bi （mass fraction） composite, the results show that the material could produce 1 480 mL H2/g with generation hydrogen rate 975 mL/（g·mn）, at 25 ℃ at the ball-milling conditions of ball milling 3.5 h, ball matedal ratio 30 ： 1 and 500 r/min; at the other ball-milling conditions of ball milling 2 h, ball material ratio 20 ： 1 and 400 r/min, the composite has higher hydrogen generation rate and less hydrogen yield. Results of X-ray diffraction （XRD） analysis and scanning electron microscopy （SEM） analysis show that Al, LiBH4 and Bi just are mechanically mixed, they do not form a new phase in the ball milling process.