摘要
采用X射线衍射、差热分析及电化学方法 ,研究了吸氢合金LaNi5-xMx(M =Mn ,Co,Fe,Cr,Al)在高温氢化反应时的歧化行为及其反应产物的电化学性能。LaNi5-xMx 在 2 5MPa氢压和 550℃以上保温一定时间后可发生明显的歧化反应 ,并析出纳米相镍。歧化反应的程度与加热温度、时间、第三组元M及合金的生成焓关系密切。电化学交换电流密度测定表明 ,经歧化反应得到的含纳米相镍的复相组织与原始合金组织相比具有较高的吸放氢电催化活性。
X ray diffraction, thermal analysis and electrochemical analysis were used to study the disproportionation behaviour of LaNi 5- x M x in hydriding process at high temperature and the electrochemical properties of the reaction products. The results prove that the disproportionation takes place and the precipetated nano phase metallic nickel is formed at a certain temperature and time. The extent of the disproportionation reaction is closely related to temperature, heating time, substituted metal and the heat of formation of the alloys. Measurement of the exchange current density shows that the nano phase contained nickel composite structure obtained by the disproportionation reaction are better in electrocatalytic characteristics than the master alloys.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2000年第3期220-224,共5页
Journal of the Chinese Society of Rare Earths
基金
甘肃省自然科学基金项目! (ZQ -96-0 62 )资助项目
关键词
稀土
贮氢合金
歧化
电化学性能
LaNi5-xMx
rare earths
hydrogen storage alloys
disproportionation reaction
nanocrystal
electrochemical properties
