A Novel Zn-Cu Bimetallic Mixed-Component MOFs Composite for Efficient CO₂ Capture

In this work, a novel mixed-component bimetallic metal-organic framework (MOF) composite material was synthesized via a solvothermal approach, and its structural and textural properties were systematically characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), N₂ adsorption/desorption analysis, and transmission electron microscopy (TEM). Furthermore, the single-component adsorption isotherms of CO₂ and N₂ were experimentally measured and fitted to the Langmuir-Freundlich model. The CO₂/N₂ selectivity of the composite was evaluated based on the ideal adsorption solution theory (IAST). The results demonstrated that the addition of Zn²⁺ significantly enhanced the specific surface area and improved the CO₂ adsorption capacity (3.97 mmol/g at 35 °C and 1 bar), with an increase of 31.5% in comparison with the Cu-BTC/MCFs (3.02 mmol/g). Meanwhile, the Zn-Cu-BTC/MCFs had good recyclability and CO₂/N₂ selectivity up to 12.5 determined via IAST (CO₂:N₂ = 85:15).