Abstract In this paper, one kind of porous materials had been prepared by doping Mg2+ on MIL-101 materials using hydrothermal method. Based on the low-pressure nitrogen adsorption (LPNA), X-Ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and High-pressure methane adsorption (HPMA) analyzer, the characteristics of new materials and its adsorption selectivity had been measured and analyzed systematically. Results show that doped Mg2+ would greatly increase the specific surface areas of MIL-101 by 58.2% at the most. Moreover, the pore structure of MIL-101 @ Mg2+ materials tend to be uniform. Compared with MIL-101 parental material, the single crystal size would be decreased by 100–200 nm. From XRD and TEM results, it can be concluded that the chemical skeleton structure of MIL-101 @ Mg2+ series materials are greatly similar with that of parental MIL-101 and not be destroyed by doping Mg2+. Doping Mg2+ increases the adsorption capacity of CH4 and N2 at different level because doping proper amount of Mg2+ restrains the generation of H bond, which has a positive effect on methane gas adsorption. Based on the maximum adsorption capacity and the hysteresis of adsorption and desorption curves, it can be concluded that the optimal Mg2+ doping amount is determined of 12.8%. And, according to the theory of Ideal Adsorbed Solution Theory (IAST), the separation coefficient of CH4/N2 selective adsorption also indicates that MIL-101@12.8% Mg2+ presents the largest adsorption separation coefficient and highest separation potentials.

中文翻译：

---

掺杂Mg2+对MIL-101孔结构及其对CH4/N2混合气体吸附选择性的影响

摘要 本文采用水热法在MIL-101材料上掺杂Mg2+制备了一种多孔材料。基于低压氮吸附（LPNA）、X射线光电子能谱（XPS）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、透射电子显微镜（TEM）和高压甲烷吸附（ HPMA)分析仪，对新材料的特性及其吸附选择性进行了系统的测量和分析。结果表明，掺杂Mg2+最多可使MIL-101的比表面积增加58.2%。此外，MIL-101 @ Mg2+ 材料的孔结构趋于均匀。与 MIL-101 母体材料相比，单晶尺寸将减小 100-200 nm。从 XRD 和 TEM 结果来看，可以得出结论，MIL-101@Mg2+系列材料的化学骨架结构与母体MIL-101非常相似，并且不会被掺杂Mg2+破坏。Mg2+的掺杂在不同程度上提高了CH4和N2的吸附能力，因为适量的Mg2+掺杂抑制了H键的产生，对甲烷气体的吸附有积极作用。根据最大吸附容量和吸附和解吸曲线的滞后性，可以得出结论，最佳的Mg2+掺杂量为12.8%。并且，根据理想吸附溶液理论（IAST）的理论，CH4/N2选择性吸附的分离系数也表明MIL-101@12.8% Mg2+呈现出最大的吸附分离系数和最高的分离电位。