Natural gas purification using a porous coordination polymer with water and chemical stability

Porous coordination polymers (PCPs), constructed by bridging the metals or clusters and organic linkers, can provide a functional pore environment for gas storage and separation. But the rational design for identifying PCPs with high efficiency and low energy cost remains a challenge. Here, we demonstrate a new PCP, [(Cu₄Cl)(BTBA)₈·(CH₃)₂NH₂)·(H₂O)₁₂]·xGuest (PCP-33⊃guest), which shows high potential for purification of natural gas, separation of C₂H₂/CO₂ mixtures, and selective removal of C₂H₂ from C₂H₂/C₂H₄ mixtures at ambient temperature. The lower binding energy of the framework toward these light hydrocarbons indicates the reduced net costs for material regeneration, and meanwhile, the good water and chemical stability of it, in particular at pH = 2 and 60 °C, shows high potential usage under some harsh conditions. In addition, the adsorption process and effective site for separation was unravelled by in situ infrared spectroscopy studies.