Ti-MWW分子筛与H_2O相互作用的DFT计算

A density functional theory study of Ti-MWW zeolite interaction with H_2O

运用DFT方法研究Ti-MWW分子筛与H_2O的相互作用,比较不同泛函对计算结果的影响.选取了10种不同的交换相关泛函,分别为B3LYP、B3PW91、PBE、BP86、M06-L、M06、M06-2X、M06-HF以及加入色散校正的DFT-D(B3LYP-D、B97-D)泛函.通过结构优化,考察吸附络合物的几何结构变化,比较吸附能以及BSSE校正后的结果.结果表明:加入色散校正的DFT-D(B3LYP-D、B97-D)泛函对计算弱的相互作用有明显的改善,而M06-2X、M06-HF泛函过高估计了分子间的弱相互作用,计算的吸附能明显高于其他方法所得结果.B3LYP-D泛函、M06-L泛函可以作为较适合的选择.

DFT methord was used to study the interaction of Ti-MWW zeolite with water,and the cal- culated results depending on exchange-correlation functionals were explored. We selected ten kinds of exchange-correlation functionals, namely B3LYP, B3PW91, PBE, BP86, M06-L, M06, M06-2X, M06-HF and DFT-D （B3LYP-D,B97-D） including dispersion correction. After structural optimiza- tion,the geometric structures and the adsorption energies before and after BSSE correction were ex- amined. The results indicated that the DFT-D （B3LYP-D,B97-D） functionals with dispersion correc- tion can obviously improve the calculated weak interaction. The M06-2X and M06-HF functionals have overestimated intermolecular weak interaction, resulting in the calculated adsorption energies higher than that by other methods. The B3LYP-D and M06-L functionals were proved to be suitable methods.