Polyvinylamine-loaded metal–organic framework MIL-101 for effective and selective CO2 adsorption under atmospheric or lower pressure

Abstract

Recently, selective removal of CO2 from offgas of various industries is very important, and metal–organic frameworks (MOFs) have been actively studied as a potential adsorbent. In this study, a typical MOF with a high porosity, MIL-101, was modified by loading (via ship in a bottle technique) basic polymer, polyvinylamine (PVAm), for the first time, in order to improve the performances of MIL-101 in adsorption/capture of CO2 from offgas. The obtained PVAm@MIL-101 showed highly increased selectivity (CO2/N2) and capacity in CO2 adsorption under low pressure, when suitable quantity of PVAm was introduced. Or, the adsorption selectivity and capacity of PVAm(0.7)@MIL-101 were around 11 and 2.5 times to those of pristine MIL-101, respectively at 298 K. Moreover, the PVAm(0.7)@MIL-101 was readily recycled for continuous uses and had optimum isosteric heat of adsorption (−ΔHads = 35–50 kJ/mol) for a wide range of CO2 adsorption. Therefore, loading PVAm into porous MOFs can be recommended as an attractive way to improve the performances of the MOFs in CO2 adsorption/capture from offgas under low pressure.