Computational study on enhancing SO2 capture capacity of M2(BDC)2TED (M = Mg, V, Co, or Ni)
Abstract
Along with finding and developing sustainable clean energy sources, environmental protection is highly urgent because the air is increasingly polluted by more and more toxic gases. In particular, the presence of toxic gas SO 2 seriously affects human health. Therefore, removing toxic SO 2 gas to clean the living environment is extremely urgent. Many technologies have been suggested to solve this, but they have not been effective yet. In recent years, the emergence of porous materials with ultra-large specific surface areas and ultra-high porosity has attracted the attention of scientists in SO 2 capture. Among porous materials, metal-organic frameworks are intensely interested in adsorption, separation, and other potential applications. Herein, we select the porous materials M 2 (BDC) 2 TED (M = Mg, V, Co, Ni) to study the SO 2 capture using simulation approaches. The research was performed at room temperature 298 K and pressure under 2.5 bar. Our results show that the order of metals gradually increasing the SO 2 adsorption uptake in M 2 (BDC) 2 (TED) is Co < Ni < V < Mg. Specifically, at 298 K and 2.5 bar, the amount of SO 2 adsorption is about 16 mmol/g for Mg-MOF, and about 13 – 14 mol/g for the M-MOF (M = V, Ni, Co). The study also elucidated the influencing factors that enhance SO 2 adsorption in M 2 (BDC) 2 TED, including adsorption isosteric heat, specific surface area, and pore volume. Noticeably, the specific surface areas and pore volumes of M-MOFs almost linearly enhance the SO 2 capture capability at room temperature and low pressure. Furthermore, we also elucidate the orbital interaction nature between SO 2 and M 2 (BDC) 2 (TED) MOFs in detail. Therein, the DOS peaks of the SO 2 adsorbate mainly interact with the adsorbents' C and O p orbitals below the Fermi level.