An ultra-stable Zr(IV)-MOF for highly efficient capture of SO2 from SO2/CO2 and SO2/CH4 mixtures

Abstract

• A novel ultra-stable Zr(IV)-MOF (HBU-20) was synthesized by solvothermal method. • HBU-20 shows highly efficient capture of SO 2 over CO 2 and CH 4 . • Theoretical simulations exhibit the importance of host–guest weak interactions. • Gas breakthrough experiments prove its’ application in deep desulfurization. Flue gas and natural gas deep desulfurization is still very challenging, so new absorbent is highly desired. In this work, a novel stable porous Zr(IV)-MOF (HBU-20) has been designed and synthesized. HBU-20 possesses a high BET surface area of 1551.1 m 2 /g and the pore volume achieves 0.896 cm 3 /g. More importantly, the compound shows a high SO 2 adsorption capacity of 6.69 mmol/g at 298 K and 100 kPa, and the higher IAST selectivitives of SO 2 /CO 2 (v/v, 1:99, 56.7) and SO 2 /CH 4 (v/v 1:99, 246) have been accordingly obtained. Theoretical simulations proved host–guest interactions should be responsible for efficient SO 2 capture. Furthermore, the excellent separation performance of HBU-20 had also been evaluated by dynamic breakthrough experiments under ambient condition. The experimental selectivities of SO 2 /CO 2 and SO 2 /CH 4 (v/v 1:99) achieve 81.1 and 117.6, respectively. The research indicates HBU-20 is a promising absorbent for deep desulfurization of flue gas and natural gas.