氢化氧化铝的同位素效应研究  

Isotope effect of trihydride aluminum oxide

作　　者：任桂明 郑圆圆[1] 王丁[1] 王林[1] 谌晓洪[1,2] 王玲[1,2] 马敏[1] 刘华兵[1] 

机构地区：[1]西华大学物理与化学学院,成都610039 [2]西华大学先进计算中心,成都610039

出　　处：《物理学报》2014年第23期134-141,共8页Acta Physica Sinica

基　　金：四川省教育厅重点项目(批准号:14ZA0113);西华大学研究生创新基金(批准号:ycjj2014129)资助的课题~~

摘　　要：在B3LYP/6-311++G(d,p)水平上预测了Al2O3H3分子的较低能量构型.其基态构型具有C s对称性,电子态为1A′.通过研究Al2O3M3和M2(M=H,D,T)的能量E、定容热容C V和熵S,用电子振动近似讨论了Al2O3+3/2M2→Al2O3M3反应的氢同位素效应,得到了Al2O3氢化的热力学函数?H0,?S0,?G0,及平衡压力与温度的关系.研究表明,氧化物Al2O3吸附氢(氘,氚)反应的同位素排代效应顺序为氚排代氘,氘排代氢,与钛等金属的同位素排代顺序相反.但排代效应都非常弱,且随着温度的增加趋于消失.The lower energy structures of Al2O3H3 molecular clusters are optimized through DFT/B3 LYP connected with6-311g＋＋（d, p） all electrons basis set. It is found that the ground state configuration of Al2O3H3has^1A′electronic state and C s symmetry. Based on the research on energy, heat capacity at constant volume, entropy of Al2O3M3 and M2（M = H, D, T）, the hydrogen isotope effects of reactions between Al2O3 and hydrogen（deuterium or tritium） gas are studied by means of the solid electron-vibration approximation. In addition, the changes of enthalpy, entropy and Gibbs free energy, and the relation between equilibrium pressures and temperatures are presented. The investigation suggests that hydrogen can be replaced by deuterium, and deuterium can be replaced by tritium in the reactions between Al2O3 and M2with the productions of solid Al2O3M3（M = H, D, T）. This replacement sequence is opposite to the metallic isotope effect e. g. for titanium, however these replacement effects are very weak, and they are weaker and weaker as the temperature increases.

关 键 词：Al2O3M3(M=H D T) 热力学函数 同位素排代效应 吉布斯自由能改变 

分 类 号：O614.31[理学—无机化学]