A multifunctional Zr-MOF for the rapid removal of Cr2O72−, efficient gas adsorption/separation, and catalytic performance

Abstract

To achieve the selective adsorption of ions and light hydrocarbons by changing the pore structure, Zr-based metal–organic framework [Zr₆(μ₃-O)₄(μ₃-OH)₄(OH)₄(H₂O)₄(TB)₂]·2DMF·2H₂O (UPC-50) was synthesized based on 3,3′,5,5′-tetra(4-carboxyphenyl)bimesityl (H₄TB) with a steric hindrance effect under hydrothermal conditions. UPC-50 features a three-dimensional frame with two-dimensional channels and high hydrothermal and chemical stability. The Zr–OH bond in the Zr₆ cluster endows UPC-50 with excellent removal capacity for trace Cr₂O₇²⁻ in water (0.089 ppm) and efficient adsorption rate (<1 min). Moreover, through the single-component gas sorption and selectivity calculated by the IAST method, the channel of 10.6 × 16.4 Å gives UPC-50 a high adsorption capacity for C₃H₆ (252.67 cm³ g⁻¹), and also shows effective separation of C₃H₆/CH₄. The unsaturated sites on the Zr₆ cluster also impart excellent catalytic performance to UPC-50 in the catalytic cycloaddition reactions of CO₂ with epoxides. Therefore, UPC-50 is a multi-functional material with a rapid removal capacity for Cr₂O₇²⁻, efficient gas adsorption/separation, and catalytic performance.