纳米二氧化硅物理吸附乙醇的密度泛函研究

Density Functional Theory Studies on Ethanol Physisorption on Ultrafine Silica

利用密度泛函理论,采用周期性边界条件及簇方法研究了无定型纳米二氧化硅的表面结构以及其对小分子吸附物乙醇的吸附性质.计算结果表明,小簇模型在研究特定种类的吸附方面具有优势,而周期性切片模型更能真实地反映纳米二氧化硅的表面环境;乙醇在二氧化硅表面的吸附主要依赖于氢键作用,并倾向于充当氢键受体的角色.

The surface geometries of ultrafine silica and its adsorption property for ethanol had been studied by density functional theory using the small cluster model as well as the periodic model. It was found that the method of small cluster model had superiority in some cases, while the periodic model could consider the surface environment of the ultrafine silica in more details. The results indicated that the ethanol molecules were adsorbed on the silica surface mainly through hydrogen bonds, and they favored to act as hydrogen bond acceptors.