Fabrication of Functionalized UiO-66 Anchored on Disorderly Layered Clinoptilolite via Surfactant-Assisted Induction for Selective Adsorption of CO₂ and CH₄

Abstract

The amine (NH2)-functionalized UiO-66 was successfully anchored on disorderly layered clinoptilolite (CP) via surfactant (poly(ethylene glycol) (PEG) and poly(vinylpyrrolidone) (PVP))-assisted induction. The structural features and physicochemical parameters of the resultant UiO-66-on-CPs were characterized by powder X-ray diffraction (XRD) patterns, scanning/transmission electron microscopy (SEM/TEM) images, Fourier transform infrared (FT-IR) spectra, N2 sorption isotherms, and small-angle X-ray scattering (SAXS) patterns. The results demonstrated that the growth of UiO-66-NH2 nanoparticles facilitated the disorder degree of the crystal plane of CP along the a-axis, while the addition of PEG in the hydrothermal synthesis system of CP was conducive to the formation of a flower-like microstructure and the introduction of PVP was beneficial to the nucleation and growth of UiO-66-NH2 nanoparticles with a small size (40 nm) on the surfaces of the obtained CP-PEG lamellas. Finally, the gas-selective adsorption and separation performances of CO2 and CH4 were evaluated using the synthesized disorderly layered UiO-66-on-CP heterostructures as adsorbents, indicating that the NH2-functionalized UiO-66-on-CP exhibited a superior selective factor (3.66) of CO2/CH4. These results elucidated that the proposed approach is a promising strategy for constructing MOF-on-zeolite heterostructures, which may open an avenue to expand CP application and improve their performance.