分子模拟预测含配位键不饱和Cu的有机骨架(MOFs)材料的储氢性能

摘要

We reported force field predictions of hydrogen uptakes for MOFs materials that contain unsaturated coordinate copper metal complexes. The ab initio calculations were performed using RI-UMP2 method with the TZVPP basis set and BSSE correction on square-coordinated copper-acidic complex and hydrogen molecules.A force field was developed based on the ab initio energetic data. The resulting force field was applied to predict hydrogen adsorption isotherms at different temperatures and pressures using GCMC method. The ab initio results indicate that the square-coordinated copper has stronger interaction with hydrogen than tetrahedral-coordinated zinc. However, existing experimental data has not realized the potential yet. In order to predict hydrogen uptakes for similar materials, we adjusted the force field parameters using known experimental isotherm of Cu-BTC and predicted hydrogen uptakes for other three similar MOFs relative to Cu-BTC.%根据RI-UMP2方法、TZVPP基组和BSSE校正计算得到的能量数据,推导了描述氢分子与含有不饱和配位键的Cu的金属羧酸配合物相互作用的分子力学力场.用巨正则系综蒙特卡洛模拟(GCMC)计算了氢在含四方形配位Cu的有机骨架(MOFs)材料上的吸附等温线.通过对比Cu-BTC的实验吸附数据发现,虽然理论预测含有四方形配位Cu的MOFs具有比含有四面体配位Zn的MOFs与氢分子更强的相互作用,但实验合成结果未能反映这一区别.以现有的Cu-BTC实验数据为参照消除理沦计算和实验测定的系统偏差,预测了3种含有四方形配位Cu的MOFs材料的储氢能力.