AbstractConsidering the rapid increase of CO₂ emission, especially from power plants, there is a constant need for materials which can effectively eliminate post-combustion CO₂ (the main component: CO₂/N₂ = 15/85). Here, we show the design and synthesis of a Cu(II) metal-organic framework (FJI-H14) with a high density of active sites, which displays unusual acid and base stability and high volumetric uptake (171 cm³ cm⁻³) of CO₂ under ambient conditions (298 K, 1 atm), making it a potential adsorbing agent for post-combustion CO₂. Moreover, CO₂ from simulated post-combustion flue gas can be smoothly converted into corresponding cyclic carbonates by the FJI-H14 catalyst. Such high CO₂ adsorption capacity and moderate catalytic activity may result from the synergistic effect of multiple active sites.