热处理对活性氧化物晶粒尺寸的影响  

Influence of heat treatment on crystal size of active oxides

作　　者：王欣[1] 魏宗平[1] 唐电[1] 

机构地区：[1]福州大学材料研究所,福建福州350002

出　　处：《材料热处理学报》2010年第11期7-11,共5页Transactions of Materials and Heat Treatment

基　　金：国家"863"项目(2007AA03Z325);福建省重大国际合作项目(2007I002)

摘　　要：采用Pechini方法制备了以RuO2,IrO2和PdO为主的纳米晶活性氧化物,选择适当的热处理温度可获得氧化物单相组织。热处理对所制备的RuO2,IrO2和PdO晶粒尺寸影响很大。尽管随加热温度升高,晶粒尺寸增大;但温度对晶粒尺度的影响并非简单的增长关系:在所制备的3种贵金属氧化物热处理过程中均出现了两段式生长现象,可以转折点为临界温度Tc分为两段,在低于Tc的温区内,晶粒长大较快,在高于Tc的温区长大速率下降。3种活性氧化物的两段式生长,应该属于贵金属氧化物成长的特有现象。认为两段变化过程可以用线性回归方程D=bT+a加以拟合,拟合的经验方程式可用以实现工业过程对晶粒尺寸的控制。Pechini method was used to prepare the nano-phased active oxides,in which RuO2,IrO2 and PdO were the main components.Mono-phased oxides can be obtained when suitable temperatures are selected.Heat treatment has great effects on crystal size of RuO2,IrO2 and PdO.Though the size increases with temperature,there is not a simple incremental relationship between the temperature and the crystal size.The two-staged increment in the preparing processes is observed for the three active oxides during heat treatment.The crystal size grows up rapidly at temperature lower than Tc,which is the intersection temperature between the two-staged increment lines,and grows up slowly at temperature higher than Tc.It implies that the two-staged increment of crystal size with increase of temperature is a special phenomenon for precious element systems.According to the two-staged phenomena,it is suggested that the equation D = bT ＋ a,in which the constants are obtained by curve fitting based on experiment,is helpful in the industrial processes to control the sizes of the three active oxides.

关 键 词：贵金属氧化物 纳米 动力学 

分 类 号：TQ138.2[化学工程—无机化工]