Simultaneous amino-functionalization and Fe-doping modification of ZIF-8 for efficient CO2 adsorption and cycloaddition reaction

A facile one-step synthetic strategy is proposed here to realize simultaneous amine-functionalized and Fe-doping modification of ZIF-8, aiming to optimize the Lewis acidic and basic properties of ZIF-8 for enhanced CO2 adsorption and subsequent cycloaddition reaction of CO2 and epichlorohydrin under solvent-free and relatively mild conditions (0.1 MPa and 80 °C). The obtained Fe-ZIF-8-NH2 exhibits an improved CO2 adsorption capacity of 63 mmol/g as compared to that of 18 mmol/g for pristine ZIF-8 and delivers a high catalytic CO2 cycloaddition efficiency with the yield of target product of 92%, much higher than that of Fe-ZIF-8 (80%), ZIF-8-NH2 (62%) and pristine ZIF-8 (40%). The improved performance can be attributed to the introduction of abundant –NH2 groups and Fe-doping that enrich the Lewis acidity and basicity. Moreover, the obtained Fe-ZIF-8-NH2 also exhibits high chemical stability and satisfactory recycling ability, which makes the obtained sample a promising catalyst for CO2 capture and utilization.