在LiCl熔盐中直接电还原制备钕硅合金

Preparation of Nd-Si alloy by direct electroreduction of solid oxides in molten LiCl

在973 K熔融LiCl盐中,利用恒电压直接电还原Nd2O3-SiO2与Nd2O3-Si两种混合氧化物,成功制备出钕硅合金.使用金属孔洞电极,通过循环伏安法结合不同条件下电解产物的X射线衍射(XRD)、扫描电子显微镜(SEM)和能量色散谱仪(EDS)分析研究了其还原机理.结果发现,Nd2O3-SiO2的还原过程分二步进行:首先SiO2还原为单质硅,然后Nd2O3被还原同时形成钕硅合金.此外,还研究了电解电压对电解过程的影响.结果发现,还原速率随着电解电压的增加而增加,氧化物中硅的原子含量为50%左右时,容易还原得到较纯的合金.据了解这是首次运用直接电解还原氧化物的方法得到钕硅合金.

In molten LiCl salt at 973 K,Nd-Si alloy was successfully prepared by direct electro reduction of a mixed oxide of Nd2 O3-SiO2 or Nd2 O3-Si at a constant potential.The reduction mechanism was studied by CV through metal cavity electrode in conjunction with XRD,SEM and EDS results of the electrolytic products under different conditions.It was found that the reduction process of Nd2 O3-SiO2 was carried out in two steps.First,SiO2 was reduced to elemental silicon,and then Nd2 O3 was deposited on silicon to form Nd-Si alloys.In addition,the effects of the electrolysis voltage have been investigated.As a result,it was found that the reduction rate increased with the increasing of the electrolysis voltage,and it was easy to prepare pure Nd-Si alloys when the atomic content of silicon was 50%in the mixed oxides.This work first reported the preparation of Nd-Si alloy by direct electroreduction of its oxides.