基于SiC和BC5的多孔材料设计及储氢性能研究

基于金刚石结构的SiC晶体和类似金刚石结构的BC5晶体设计了多孔材料,并用分子力学方法对其进行优化得到平衡态结构.利用GCMC对其在温度为298 K和77 K,压强为0-100 bar的条件下的储氢量、氢分子密度分布和等量吸附热进行了讨论.考虑孔内壁以化学吸附的氢在内,基于SiC晶体设计的多孔材料储氢量比Si C纳米管的结果更理想.氢分子密度分布图表明氢分子在孔道中的分布距孔道边缘有一定的距离,此距离与氢分子动力学直径2.89A相当.等量吸附热表明材料在温度为298 K和77 K对氢分子的吸附都是物理吸附.

Design of Porous Materials and Research of Hydrogen Storage Properties Based on SiC and BC5

We design two kinds of porous materials based on Si C with diamond structure and BC5 with diamond-like structure. To obtain the equilibrium structure,we optimize the porous materials by the molecule mechanics method. We discuss the hydrogen storage capacity,the hydrogen molecule density distribution and the isosteric heat of adsorption by GCMC at the temperatures of 298 K and 77 K under the pressure of 0 - 100 bar. Considering the hydrogen by chemisorption in the hole inner-wall,the hydrogen adsorption amount of the Si C-based porous materials is better than that of the Si C nanotubes. The snapshot of the adsorbed hydrogen molecule density shows that the hydrogen molecules have certain distance from the hole wall of the structure and this distance equals the kinetic diameter2. 89 A of hydrogen molecule. The isosteric heat of adsorption shows that the adsorption of hydrogen molecules for the materials at the temperatures of 298 K and 77 K belongs to physical adsorption.