Bromine functionalized zirconium–fumarate frameworks for enhanced xenon capture and separation

Abstract

Design and synthesis of porous solids materials for efficient separation and capture of inert gas Xe and Kr from the nuclear off-gas steam remain urgent and challenging issues. Herein, a new bromine functionalized Zr-based metal organic framework (MIP-203-F-Br) was successfully prepared using a facile synthetic method to effectively separate and capture Xe and Kr. The immobilization of bromine atoms into framework of MIP-203-F-Br creates a highly polarized pore environment in its 1D-channel with optimized pore size (4.6 Å), that maximizes confinement effects for Xe absorption. MIP-203-F-Br exhibits significantly high Xe adsorption affinity at low pressure with a high Xe uptake capacity (39.4 cm³·cm⁻³) at 10 kPa and 298 K and a record-breaking Henry-coefficient (27.2 mmol·g⁻¹·bar⁻¹) among the reported Zr-based MOFs. Through the breakthrough experiments carried out in dilute conditions (simulation of nuclear off-gases), the practical separation performance of MIP-203-F-Br was confirmed. Grand Canonical Monte Carlo (GCMC) simulations and Density Functional Theory (DFT) calculations were performed to elucidate the adsorption mechanism in MIP-203-F-Br, highlighting the significant role played by Br atoms in enhancing Xe adsorption. This work also provides a novel facile synthetic method to achieve bromine functionalized MOFs for potential various applications.