γ-Al_2O_3转化为α-Al_2O_3的热力学分析  

Thermodynamic Analysis of Phase Transition of γ-Al_2O_3 to α-Al_2O_3

作　　者：史建公[1] 刘志坚[2] 李卫红[1] 罗道威[1] 张毅[1] 张敏宏[1] 

机构地区：[1]中国石化催化剂北京燕山分公司,北京102400 [2]中国石化催化剂有限公司,北京102900

出　　处：《化学世界》2014年第7期385-388,391,共5页Chemical World

摘　　要：γ-Al2O3和α-Al2O3都是氧化铝的重要存在形式,都是催化剂的常用载体。γ-Al2O3在热力学上是不稳定的,经高温焙烧或研磨等可以转化为α-Al2O3。采用业界公认的热力学数据,首次对γ-Al2O3转化为α-Al2O3的热力学进行了分析。结果表明,在298.15～1000K范围内,这种相转变属于放热反应,且随温度升高,放热量增大;同时其自由能变化小于0,但随温度升高,自由能负值越来越小。这是因为这一相变反应为熵减过程。γ-Al2O3andα-Al2O3are important forms of alumina and are used as supports in catalysts widely.γ-Al2O3is unstable in thermodynamics and can be converted intoα-Al2O3by means of high temperature roasting or grinding,etc.Thermodynamic analysis of phase transition ofγ-Al2O3toα-Al2O3 was carried out within the scope of 298.15to 1000Kfirstly with thermodynamic data recognized by peers.The results show that the phase transition is an exothermic reaction,and the heat released increases with temperature.Its free energy change is less than zero simultaneously and increases gradually along with the rising in temperature.This is because the phase change is an entropy reduction process.

关 键 词：Γ-AL2O3 Α-AL2O3 相转变 热力学 

分 类 号：TF8[冶金工程—有色金属冶金] TQ021.2[化学工程]