高氯酸锂分解动力学研究

Kinetic study of lithium perchlorate decomposition mechanism

通过高温热重-差示扫描量热(TG-DSC)同步热分析手段,在N2气氛下研究了5种不同升温速率下LiClO4的分解过程,试验温度范围从常温到900℃。分别从化学反应过程中的质量变化和能量特性两方面研究了LiClO4分解的动力学机理。通过TG和DSC数据获得2组转化率数据αTG和αDSC。对比发现,αDSC滞后于αTG,并且随升温速率的升高,αDSC的滞后也更加严重。采用单扫描速率法拟合数据发现,分解过程可分为2个阶段,需要采用2个不同的机理函数拟合。采用多重扫描速率Friedman方法分别拟合TG和DSC数据,得到了2组活化能数据。

The lithium perchlorate decomposition process under N2 atmosphere by five different heating rates was analyzed with TG-DSC simultaneous thermal analysis in the temperature range of room temperature to 900℃. Kinetic mechanism of lithium per- chlorate decomposition was analyzed by both mass-change rate and energy performance of the chemical reaction process. αTG and αDSC were obtained from TG and DSC data,respectively. It was found that in the same heating-rate αDSC lags behind of and the de- lay increases with the increase in heating-rate. The decomposition process was divided into two-step consecutive reaction which should be fitted with two different mechanism function by single-scan rate method. The multi-scan rate method Friedman was applied to obtaining two sets of activation energies calculated from TG and DSC data respectively.