【作者】 覃吴；

【导师】 李欣；

【作者基本信息】 哈尔滨工业大学 ， 化学工程与技术， 2007， 硕士

【摘要】 以Al₂O₃为载体,用浸渍法分别制备了CuO和Fe掺杂CuO两种催化剂。通过UV254的测定,测得单独臭氧氧化去除率为21.5%,CuO和Fe掺杂CuO催化剂的去除率分别为44.8%和55.0%。CuO和Fe掺杂CuO催化剂都有催化活性,其中Fe掺杂CuO催化剂具有更好的催化活性。用SEM分析了CuO催化剂和Fe掺杂CuO催化剂的表面结构。用XPS分析了Fe掺杂CuO催化剂,得到催化剂表面元素组成、元素相对含量和元素价态。用层模型方法分别建立了催化剂的理想表面模型Y1（铜终止面）和Y2（氧终止面）、掺杂表面模型Z1（铜终止面）和Z2（氧终止面）以及负载型表面模型。采用密度泛函理论的广义梯度近似和PW91基组,对表面模型进行几何优化,得到各个表面的稳定构型。首先,用密度泛函理论计算分析了单层O3在表面模型上吸附后的结构变化和电子特性。单层O3在Y1和Y2模型上的吸附能分别是-8.7442eV和0.3712eV,在Z1和Z2模型表面上的吸附能分别是-8.4295eV和-8.4395eV,在负载型表面模型上的吸附能是-8.7271eV。从吸附能数据分析可知,除了Y2模型,其它四种模型均与O3有较强的相互作用。进一步计算了O3在这五种模型上吸附的电荷分布、电子转移、轨道分裂和轨道能量的变化,计算结果表明:除了Y2模型,其它四种模型均能使吸附的O3分解成O和O2。其次,计算分析了两层O3在表面模型Y1和Y2上吸附后的结构变化和电子特性。O3在Y1和Y2模型上的吸附能分别是-8.8075eV和-2.8442eV。进一步计算O3在这两种模型上的电荷分布、电子转移、轨道分裂和轨道能量的变化,计算结果表明:O3在Y1模型上吸附分解成O和O2。综合各种模型的计算结果,CuO和Fe掺杂CuO催化剂表面都有催化活性,其中Fe掺杂CuO催化剂表面具有更好的催化活性,这和催化剂性能测试结果相一致。更多还原

【Abstract】 The alumina supported catalysts CuO/Al₂O₃and Fe-doped CuO/Al₂O₃ wereprepared by immersion method. The UV254 removal of independent ozonation,CuO/Al₂O₃ catalytic ozonation and Fe-doped CuO/Al₂O₃ catalytic ozonation is21.5%, 44.8% and 55.0% respectively, which shows that both CuO/Al₂O₃and Fe-doped CuO/Al₂O₃ display high catalytic activity. Especially, The Fe-dopedCuO/Al₂O₃ is more active than CuO/Al₂O₃ during water treatment. The surfacestructures of catalyst were characterized by scanning electron microscopy. X-rayphotoelectron spectroscopy was used to analyze the component, elementpercentage composition and element valence of the Fe-doped CuO/Al₂O₃.Layer-model method was used to build the ideal surface models （the Cu-termination surface model Y1 and the O-termination surface model Y2）, thedoped surface models （the Cu-termination surface model Z1 and the O-termination surface model Z2） and the loaded surface model, the stable structuresof which were obtained after geometrical optimization by using densityfunctional theory within the generalized gradient approximation and the PW91implementations.For the interaction to single-layer ozone, according to the calculation based ondensity functional theory, this work analyzed the structural change and electronicproperty. The adsorption energies of Y1 and Y2 are -8.7442eV and 0.3712eVrespectively, and those of Z1 and Z2 are -8.4295eV and -8.4395eV respectively,and that of the loaded surface model is -8.7271eV, which showed that all thesurface models interacted with ozone strongly except Y2. Further calculationabout atomic charge population, electron transfer, break of atomic orbit andorbital energy showed ozone decomposed into oxygen atom and oxygenmolecular on all the surface models exceptY2.For the interaction to double-layer ozone, the structural change and electronicproperty were also discussed after the calculation based on density functionaltheory. The adsorption energies of Y1 and Y2 are -8.8075eV and -2.8442eVrespectively. Further calculation also was done to analyze atomic chargepopulation, electron transfer, break of atomic orbit and orbital energy, which showed that ozone decomposed onY1.According to the arguments presented above, the surface models of theCuO/Al₂O₃and the Fe-doped CuO/Al₂O₃, display catalytic activity to ozonation,and the present of Fe increase the catalytic activity of catalyst surface, whichmatch the results of the catalytic activitytest above verywell.更多还原