Enhanced CH₄/N₂ Separation Efficiency of UiO-66-Br₂ through Hybridization with Mesoporous Silica

Efficient separation of CH₄ from N₂ is essential for the purification of methane from nitrogen. In order to address this problem, composite materials consisting of rod-shaped SBA-15-based UiO-66-Br₂ were synthesized for the purpose of separating a CH₄/N₂ mixture. The materials were characterized via PXRD, N₂ adsorption-desorption, SEM, TEM, FT-IR, and TGA. The adsorption isotherms of CH₄ and N₂ under standard pressure conditions for the composites were determined and subsequently compared. The study revealed that the composites were formed through the growth of MOF nanocrystals on the surfaces of the SBA-15 matrix. The enhancements in surface area and adsorption capacity of hybrid materials were attributed to the structural modifications resulting from the interactions between surface silanol groups and metal centers. The selectivity of the composites towards a gas mixture of CH₄ and N₂ was assessed utilizing the Langmuir adsorption equation. The results of the analysis revealed that the U6B2S5/SBA-15 sample exhibited the greatest selectivity for CH₄/N₂ adsorption compared to the other samples, with an adsorption selectivity parameter (S) of 20.06. Additional research is necessary to enhance the enrichment of methane from CH₄/N₂ mixtures using SBA-15-based metal-organic framework materials.