Polyethyleneimine Incorporated Metal-Organic Frameworks Adsorbent for Highly Selective CO2 Capture

Abstract

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 CO2 adsorption capacity at low pressures. At 100 wt% PEI loading, the CO2 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 CO2 over N2 in the designed flue gas with 0.15 bar CO2 and 0.75 bar N2. The CO2 over N2 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 CO2 capture.

Development of monolithic adsorbent via polymeric sol–gel process for low-concentration CO2 capture

“…However, for chemical adsorption with amine-based adsorbents, CO 2 capacity is mainly affected by the amine content in the adsorbents and there should be no direct relationship between surface area and CO 2 capacity of amine-based chemical adsorption adsorbents, as the CO 2 capacities of these adsorbents result from the reaction with amine groups. For example, it has been found from our research and others' studies that the sample with higher amine loading and lower surface area presents a higher CO 2 adsorption capacity [21,35,36,[86][87][88]. This is explained by that the loaded moieties on the adsorbents' surface could block the pore space of the porous/solid adsorbents [21,35,36].…”

Vapor-enhanced CO2 adsorption mechanism of composite PEI@ZIF-8 modified by polyethyleneimine for CO2/N2 separation

“…These peaks get stronger with the increasing loading PEI due to the hydrophilic surface of PEI. The peaks at 2838 cm À1 clearly observed in the IR spectra of PEI@ZIF-8 samples can be assigned to m (-NH-) stretching vibrations [29], characteristic peak of amine functional groups in PEI. It was observed that the intensity of the peak at 2838 cm À1 increased with an increase in PEI loading.…”

“…Lin and Chen et al [29] tried to prepare a PEI incorporated MIL-101, and reported that the resulting composites exhibited obviously enhanced CO 2 adsorption capacity at low pressures, and the adsorption isotherms of CO 2 on dry and humid PEI-MIL-101(Gr) samples were nearly the same, indicating no negative effect of water adsorption on the CO 2 adsorption, which is interesting. However, to the best of our knowledge, the work about functionalization of MOFs with PEI has been rarely reported.…”

Desorption Kinetics and Mechanisms of CO2 on Amine-Based Mesoporous Silica Materials

“…Fast adsorption kinetics is one of the most important properties when evaluating a good adsorbent [20][21][22][23]. Currently, a lot of kinetic models are proposed to describe the experimental data.…”