镧镍体系(LaNi_(5-x)Mx)吸氢化合物的研究(Ⅰ)——LaNi5的化学合成及吸氢性能

STUDIES ON THE La-Ni SYSTEM OF HYDROGEN ABSORPTION COMPOUNDS--Ⅰ——A CHEMICAL SYNTHETIC METHOD AND HYDROGEN ABSORPTION PROPERTIES OF LaNi_(5)

过渡金属氢化物因与氢能源的利用紧密有关,近年来在国际上引起极大注意。本文提出了吸氢化合物LaNi_(5)的一种新的合成方法——共沉淀还原法,并详细研究了反应过程。首先通过水溶液反应生成镧镍草酸盐共沉淀,脱水后,该沉淀与氢化钙在950℃反应生成LaNi_(5).

In this paper a new route to the preparation of LaNi_(5) by chemical synthetic method is presented.Lanthanum Nickel oxalate was first prepared by coprecipitation reactions from aqueous solutions,and the oxalate formed after dehydration was reduced by CaH2 at 950℃to give LaNi_(5).The reaction was studied in detail and the lattice parameters ofLaNi_(5) were found a0=5.003 A and c0=3.987A.The LaNi_(5) thus prepared shows excellent absorption ability for hydrogen and the hydride formed has the composition corresponding to LaNi_(5)H6.1The method seems to have general utility for chemical preparation of some transition metal alloys and intermetallic compounds.In this paper a new route to the preparation of LaNi_(5) by chemical synthetic method is presented.Lanthanum Nickel oxalate was first prepared by coprecipitation reactions from aqueous solutions,and the oxalate formed after dehydration was reduced by CaH2 at 950℃to give LaNi_(5).The reaction was studied in detail and the lattice parameters ofLaNi_(5) were found a0=5.003 A and c0=3.987A.The LaNi_(5) thus prepared shows excellent absorption ability for hydrogen and the hydride formed has the composition corresponding to LaNi_(5)H_(6.1).The method seems to have general utility for chemical preparation of some transition metal alloys and intermetallic compounds.