Surpassing stoichiometric limitation for supra-multi-molar adsorption and separation of acid gases

Capture of acid gases holds crucial importance for addressing air pollution and climate change, where achieving a molar ratio for adsorption and separation of acid gases on an active site higher than 1.0 remains challenging. Herein, we demonstrate that three nitrogen-bonded one Zn sites within a single-crystalline-like porous carbon (Zn-N₃@SC-PC) derived from controlled carbonization of ZIF-8-C ≡ N with KCl, exhibit supra-multi-molar adsorption for CO₂, COS, and H₂S, even to 1:6 ratio for SO₂ on the Zn-N₃. This exceptional performance is attributed to the protruded structure in the Zn-N₃@SC-PC for more coordination between Zn vacant orbital and acid gases evidenced by DFT calculation and in situ EXAFS. The high capacity for capturing acid gases on this adsorbent is crucial for future in carbon neutrality and environment protection.