【摘要】 采用基于密度泛函理论(DFT)的第一性原理方法研究了CO和Cl2分子在TiO2(110)面上的吸附反应,通过计算体系的吸附结构、吸附能、电荷密度和态密度等性质,揭示了CO和Cl2共同吸附在TiO2(110)表面的行为机制。CO和Cl2在TiO2(110)面上的吸附存在相互促进的关系,共同吸附时其平均吸附能为-1.367 4eV,Cl2能够被表面Ti原子捕获,表面Ti(5c)原子发生sd3轨道杂化,吸附发生时表面形成CO→TiO2(110)→Cl流向的瞬时电子流,态密度的分布显示TiO2(110)表面的Ti-O键强度被削弱,说明CO的存在对TiO2的氯化有促进作用,同时表面O原子被激活,其随着CO从表面解离形成CO2分子平均释放1.418 6eV的能量,使得TiO2(110)结构被破坏,同时也为下一个Cl2分子提供了良好的吸附位。更多还原

【Abstract】 The first principle calculation based on density functional theory(DFT)is used in this paper to investigate the adsorption behavior of CO and Cl2 on TiO2(110)surface.The behavioral mechanism of the co-adsorption of CO and Cl2 on the TiO2(110)surface is revealed by the calculation of the adsorption structure,adsorption energy,charge density and density of states(DOS)of the system.The adsorption of both CO and Cl2 on the TiO2(110)surface was mutually reinforcing,and the average adsorption energy was-1.367 4 eV,and Cl2 could be captured by the surface Ti atom,the sd3 orbital hybridization happening on the surface Ti(5 c)atom.When the adsorption reaction occurred,a transient electron flow CO→TiO2(110)→Cl was formed on the surface.The DOS showed that the strength of Ti-O bond on(110)surface was weakened,indicating that the presence of CO has a promoting effect on the chlorination of TiO2.Meanwhile,the surface O atoms was activated and the average energy of 1.418 6 eV was released as the dissociation of this O atom with CO from the surface to form CO2 molecules,which destroyed the structure of TiO2(110)and provided a good adsorption site for the next Cl2 molecules.更多还原