Functionalised modified metal–organic framework materials for CO2 capture and separation

The strategic development of lithium-engineered metal–organic frameworks (MOFs) for high-performance CO2 capture represents a critical pathway toward achieving net-zero emissions. Herein, we report three novel 2D copper-based MOFs coordinated with planar π-conjugated ligands, followed by targeted –OLi functionalisation via post-synthetic modification. –OLi groups induce electrostatic polarisation through Li→O charge transfer, creating strong Li–CO2 interactions and spatial confinement via optimised pore geometry. The functionalised 2DMOF_n-OLi systems demonstrate exceptional CO2 uptake capacities of 3.30–5.68 mmol·g−1 at 298 K/1.0 bar, with record CO2/N2 and CO2/CH4 selectivities reaching 15,456.5 and 7239.9 respectively, surpassing benchmark materials (e.g. Mg-MOF-74: 4.21 mmol·g−1). This dual-modification strategy (electronic structure engineering and pore geometry control) establishes a universal design paradigm for developing advanced sorbents, with demonstrated potential for direct air capture applications.To mitigate atmospheric CO2 concentrations, three metal–organic frameworks were designed and functionalised by doping with –OLi functional groups, showing ultra-high CO2 capture and separation.