An In(III)-MOF based on pore engineering for efficient capture SF6 from SF6/N2 mixture

Efficient capture of greenhouse gases (SF6 and CO2) is crucial for addressing global climate issues and is highly challenging. Reasonably designing MOFs with expected functions based on pore engineering can help solve the problem. In the present work, a trinuclear cluster based In(III)-MOF (HBU-21) was designed and synthesized, which shows a three-dimensional (3D) network. The BET specific surface area reaches 381.44 m2⋅g-1. Importantly, the appropriate pore size (6.14 Å) is very suitable for selective capture of SF6 from SF6/N2 mixture. The higher IAST selectivity was obtained (SF6/N2, v/v 10:90, 184.05; 1:99, 88.87). In addition, HBU-21 also shows high uptakes of C2H2 and CO2, the capacities achieve 45.21 cm3⋅g−1 and 24.36 cm3⋅g−1 at 298 K 100 kPa, respectively. Theoretical simulations results indicate that the open metal site (OMS) should be responsible for the different adsorption behavior. To further validate its potential application value, recycling experiments were further implemented. The maximum adsorption capacity of SF6 remains basically unchanged after three rounds of adsorption and desorption tests. The results provide certain reference for rational designing MOFs based on pore engineering.