Polyethyleneimine Incorporated Metal-Organic Frameworks Adsorbent for Highly Selective CO(2) Capture

A series of polyethyleneimine (PEI) incorporated MIL-101 adsorbents with different PEI loadings were reported for the first time in the present work. Although the surface area and pore volume of MIL-101 decreased significantly after loading PEI, all the resulting composites exhibited dramatically enhanced CO(2) adsorption capacity at low pressures. At 100 wt% PEI loading, the CO(2) adsorption capacity at 0.15 bar reached a very competitive value of 4.2 mmol g(−1) at 25°C, and 3.4 mmol g(−1) at 50°C. More importantly, the resulting adsorbents displayed rapid adsorption kinetics and ultrahigh selectivity for CO(2) over N(2) in the designed flue gas with 0.15 bar CO(2) and 0.75 bar N(2). The CO(2) over N(2) selectivity was up to 770 at 25°C, and 1200 at 50°C. We believe that the PEI based metal-organic frameworks is an attractive adsorbent for CO(2) capture.