TiH_( 1.971)催化Mg纳米晶储氢性能研究

Study on hydrogen storage property of nanocrystalline Mg catalyzedby TiH_( 1.971)

采用湿化学球磨法制备了Mg+TiH_( 1.971)复合体系,并以对比分析法研究了催化剂Mg+TiH_( 1.971)对Mg纳米晶的储氢性能改善效果.研究结果表明,Mg+TiH_( 1.971)纳米晶复合体系在室温下20℃左右就能开始吸氢,而Mg纳米晶则需40℃.吸氢后的Mg+TiH_( 1.971)(w(TiH_( 1.971))=5%)在220℃下开始放氢,比吸氢后的Mg纳米晶低了55℃.等温吸氢结果显示,在100℃下,Mg+TiH_( 1.971)(w(TiH_( 1.971))=5%)在10 min内,吸收2.8%的氢气,比Mg纳米晶的吸氢量多了33%.同时,吸氢表观活化能从Mg纳米晶的26.7±0.1 kJ/mol降低至Mg+TiH_( 1.971)(w(TiH_( 1.971))=5%)的20.9±1.8 kJ/mol.TiH_( 1.971)的掺杂对Mg纳米晶的储氢性能改善较明显,为下一代更高性能的储氢材料的研发提供了思路.

TiH_( 1.971) as catalyst was added into Mg to synthesize Mg+TiH_( 1.971) composite via wet chemical ball milling.The comparative analysis method was used to study the improvement effect of the catalyst Mg+TiH_( 1.971) on the hydrogen storage performance of Mg nanocrystals.The results show that the composite starts to take up hydrogen at about 20℃,while nanocrystalline Mg needs 40℃.The hydrogenated sample starts to release hydrogen at 220℃,the temperature of which is 55℃ lower than that of the hydrogenated nanocrystalline Mg.The isothermal hydrogen absorption results show that the sample absorbs 2.8%hydrogen within the first 10 min at 100℃,33%higher than the temperature for nanocrystalline Mg.Meanwhile,the apparent activation energy for hydrogenation decreased from 26.7±0.1 kJ/mol(nanocrystalline Mg)to 20.9±1.8 kJ/mol(Mg+5%TiH_( 1.971)).The addition of TiH_( 1.971) improves the hydrogen storage performance of nanocrystalline Mg,which sheds light on the development of next-generation higher-performance hydrogen storage materials.