H2O2稳定性的密度泛函研究

程 学 礼

(泰山学院 化学化工学院，山东 泰安 271000)

1 前言

双氧水(H2O2)是一种清洁氧化剂而被广泛用于造纸和化学合成[1]，能够参与多种氧化还原反应[2-4].H2O2还常被用于有机污染物的降解[5-7]，著名的芬顿反应就是用H2O2和Fe2+的混合溶液氧化有机化合物，特别是难降解有机污染物[8-9].

H2O2可以通过氢气和氧气直接反应或氧气电还原等方法低成本合成[10-11].然而，无论在气相还是溶液中H2O2均不稳定，易分解释放氧气(ΔH=-98.23 kJ/mol)；H2O2对光照敏感，双氧水在λ= 275-366nm下均可分解[12-13].在金属阳离子、碘离子和金属氧化物催化下，H2O2能够快速分解[14-17].一般情况下，H2O2分解为2个羟基自由基参与反应，因此，O-O键长的变化在H2O2分解过程中将扮演重要角色.

2 计算方法

3 结果与讨论

3.1 基态结构

图1 B3LYP和M06-2X方法结合得到的分子结构(键长的单位是nm，括号内为气相键长)

3.2 发射光谱

表1 TD-M062X模拟得到的4种结构发射光谱的最大发射波长λmax(振子强度f)和跃迁轨道(跃迁贡献比). λmax以nm为单位.方括号内数据为气相数据

3.3 激发态结构

图2 T1态优化结构参数

4 结论

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