A pillared-layer metal–organic framework for efficient separation of C3H8/C2H6/CH4 in natural gas

Metal–organic frameworks (MOFs) have great potentials as adsorbents for natural gas purification. However, the trade-off between selectivity and adsorption capacity remains a challenge. Herein, we report a pillared-layer metal–organic framework Ni(HBTC)(bipy) for efficiently separating the C3H8/C2H6/CH4 mixture. The experimental results show that the adsorption capacity of C3H8 and C2H6 on Ni(HBTC)(bipy) are as high as 6.18 and 5.85 mmol·g–1,while only 0.93 mmol·g–1 for CH4 at 298 K and 100 kPa. Especially, the adsorption capacity of C3H8 at 5 kPa can reach an unprecedented 4.52 mmol·g–1 and for C2H6 it is 1.48 mmol·g–1 at 10 kPa. The ideal adsorbed solution theory predicted C3H8/CH4 selectivity is as high as 1857.0, superior to most of the reported materials. Breakthrough experiment results indicated that material could completely separate the C3H8/C2H6/CH4 mixture. Therefore, Ni(HBTC)(bipy) is a promising material for separation of natural gas.