Ti基催化剂对SrAl_2合金催化吸氢研究

Hydrogenation Properties of SrAl_2 Alloy Doped with Ti-Based Catalysts

先采用感应熔炼法制备SrAl2合金,然后采用机械球磨方法分别添加摩尔分数为x=2%的TiF3、Ti及TiO2催化剂,从而得到不同Ti基催化剂添加的Zintl相合金SrAl2;并将未添加催化剂的SrAl2合金用于对比研究。采用XRD、SEM、EDS、PCT及XPS设备研究了材料的相结构、表面形貌、吸氢性能与催化机理。研究表明:3种Ti基催化剂对Zintl相合金SrAl2的吸氢均能起到催化作用,催化强弱次序如下:TiF3>Ti>TiO2。对添加Ti基催化剂的SrAl2合金吸氢前后的表面XPS研究分析表明:合金表面Ti 2p电子的结合能发生了改变,说明其化学状态发生了变化。特别是添加了TiF3的合金样品中出现了单质Ti0,这种在反应过程中生成的中间产物Ti0要比刚开始在合金中加入的单质Ti具有更高的催化活性。

Phase structure,surface morphology,hydrogenation property and catalytic mechanism of the Zintl phase alloy SrAl2 doped with 2 mol.% Ti-based catalysts（including TiF3,Ti and TiO2） were investigated systematically by means of XRD,SEM,EDS,PCT and XPS.It was shown that the three Ti-based catalysts can improve the hydrogenation kinetics of the SrAl2 alloy,and the catalytic effect followed the order of TiF3TiTiO2.XPS analysis of the alloy before and after hydrogenation indicated that the binding energy of Ti 2p on the alloy surface changed upon hydrogenation.Particularly,Ti0 was observed in the TiF3-doped SrAl2 alloy.The intermediate product of Ti0 has great catalysis on hydrogenation of SrAl2,and the catalytic effect of Ti0 is better than Ti doped initially,leading to the best hydrogenation kinetics of TiF3-doped SrAl2 alloy.