La-O小团簇上超氧物种与过氧物种间的连接途径(英文)  

Pathways between superoxide and peroxide species on small La-O clusters

作　　者：夏文生[1] 张达[1] 翁维正[1] 万惠霖[1] 

机构地区：[1]厦门大学化学化工学院福建省理论与计算化学重点实验室醇醚酯清洁化工生产国家工程实验室/固体表面物理化学国家重点实验室,福建厦门361005

出　　处：《催化学报》2013年第11期2130-2137,共8页

基　　金：supported by the National Basic Research Program of China (973 Program, 2010CB732303);the National Natural Science Foundation of China (21033006, 21373169, 20373054);the Program for Changjiang Scholars and Innovative Research Team in the University (IRT1036)~~

摘　　要：采用密度泛函理论方法考察了La-O团簇上超氧物种与过氧物种间转化的连接途径.单重态下,团簇上单个超氧物种可通过一系列臭氧物种转化为过氧物种,且转化能垒较高;三重态下,单个超氧物种则并无与过氧物种间连接的途径.然而,La-O团簇上两超氧物种间的相互作用及其转化也具单重态和三重态两条途径.三重态下,超氧物种可很容易地转化为过氧物种(O2+O2O22+O2),超氧物种与过氧物种处于快速的交换状态之中;单重态下,超氧物种转化为过氧物种则需较高的活化能垒,表明在单重态下这些氧物种具有较高的稳定性.Density functional theory calculations were used to investigate the connection between superoxide and peroxide species on La-O clusters.In the singlet state,a superoxide species can transition into a peroxide species by moving through a substantial energy barrier via a series of ozonides.In the triplet state,there is no connection between the two species,although there are two paths(singlet and triplet) that allow the interaction and subsequent transformation of two superoxide molecules on a La-O cluster.The superoxide species readily transitions to a peroxide species through a triplet pathway(O2–+ O2– O22– + O2),in which the superoxide species undergoes rapid exchange with the peroxide.In the singlet path,however,the superoxide species must move through a pronounced energy barrier to change into a peroxide species,demonstrating that these oxygen species are high- ly stable in the singlet state.

关 键 词：氧 超氧 过氧 氧化镧 密度泛函理论 

分 类 号：O621.25[理学—有机化学]