A Highly Chemically Robust 2D Zn-MOF as Promising Adsorbent for One-Step Methane Purification From Multicomponent Gas...

One-step CH₄ purification from C₂-hydrocarbons and CO₂ gas impurities is essential in the quest for clean energy resources amidst the growing energy crisis. While MOF materials have demonstrated significant progress in binary C₂H₂/CH₄, C₂H₄/CH₄, C₂H₆/CH₄, and CO₂/CH₄ separations, there is a growing emphasis on the purification of CH₄ from multicomponent gas mixtures using a single adsorbent. Toward this direction, a 2D MOF: IITKGP-27, {[Zn(MBPz) (SO₂DBA)]·4H₂O}_n featuring rhombus pores decorated with polar functionalities has been strategically constructed displaying remarkable chemical robustness in water for 7 days, across a wide range of aqueous pH solutions (pH = 2-12), and in open air for 30 days. Interestingly, IITKGP-27 selectively adsorb C₂ hydrocarbons (C₂H₂, C₂H₄, and C₂H₆) and CO₂ over CH₄, attributed to the synergistic effect of favorable host-guest (C₂S and CO₂) interactions due to the presence of accessible surface functionalities and optimal pore apertures. Moreover, an excellent trade-off between high sorption capacities and moderate separation selectivities was achieved. Transient breakthrough simulations further validated its feasibility toward unexplored CH₄ purification from a blend of all such five gases mimicking natural gas composition, demonstrating its viability for this critical application. In addition, the facile bulk scalability, ease of regeneration, excellent recyclability, and outstanding structural stability highlight its potential as a robust solution for efficient CH₄ purification from natural gas streams.