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以SiO2簇模型为基体,通过Ti原子取代建立Ti中心原子上连接0个或1个OH基团的典型SiO2-TiO2复合氧化物模型来模拟处于体相中和表面上的四配位Ti(IV)中心.采用广义梯度近似的密度泛函理论(DFT-GGA)研究了CuCl与SiO2-TiO2载体的相互作用.计算结果表明,在SiO2基体中嵌入Ti(IV)离子可以大大加强CuCl与氧化物载体之间的相互作用,使CuCl/SiO2-TiO2催化剂的结构更稳定.分子前线轨道表明Cu(I)作为催化剂的活性中心贡献了HOMO轨道,容易失去电子;Ti(IV)中心原子贡献LUMO轨道,容易得到电子,计算结果与实验事实相一致.
Based on the SiO2 cluster model, a typical SiO2-TiO2 composite oxide model in which zero or one OH group is attached to the central Ti atom was substituted by Ti atom to simulate the tetracoordinate Ti (IV ) Center.The density functional theory (DFT-GGA) of generalized gradient approximation was used to study the interaction between CuCl and SiO2-TiO2 carrier.The calculated results show that the insertion of Ti (IV) ions in the SiO2 matrix can greatly enhance the interaction between CuCl and oxide The structure of CuCl / SiO 2 -TiO 2 catalyst is more stable due to the interaction between the carriers.The molecular frontier orbital indicates that Cu (I) as the active center of the catalyst contributes to the HOMO orbital and easily lose electrons. The central atom of Ti (IV) contributes to the LUMO orbit , Easy to get the electrons, the calculation results are consistent with the experimental facts.