Highly efficient separation of 1, 3-butadiene from nitrogen mixture by adsorption on highly stable MOF

For separating 1, 3-butadiene (BD) from BD/N₂ mixture, among numerous studied metal–organic frameworks-based adsorbents, Ni-ZIF-8 was comparatively selected here based on intelligent gravimetric analysis, simulation studies, facile synthesis, and very good IAST selectivity. Experimental results showed good butadiene uptake capacity of Ni-ZIF-8 of 7.41 mol/kg, which is 42% higher than pure ZIF-8. Additionally, Ni-ZIF-8 exhibits IAST selectivities of 2826 and 3302 at 0.1 bar, at 25 and 45 °C respectively, for 20% BD/N₂ adsorption. The molecular simulation results showed that Ni-ZIF-8 has binding energies of 65.25, 9.54 kJ/mol, while ZIF-8 has 56.07, 15.03 kJ/mol for butadiene, and nitrogen, respectively. This strongly supported the experimental results. To the best of our knowledge, Ni-ZIF-8 showed the best working capacity of 5.91 mol/kg for butadiene among all the reported adsorbents. Moreover, dynamic adsorption experiments revealed that butadiene could be recovered from BD/N₂ mixtures at room temperature, suggesting great potential for industrial BD/N₂ separation.