Hierarchical mesoporous organic polymer with an intercalated metal complex for the efficient synthesis of cyclic carbonates from flue gas

Abstract

CO₂ capture and utilization is one of the most attractive and challenging topics of the twenty-first century. The direct conversion of CO₂ using flue gas as a feedstock is an energy saving process, but it has been rarely reported. Herein, we report an efficient CO₂ cycloaddition reaction using diluted gas (20% CO₂ and 80% N₂, simulating flue gas) as a feedstock, catalyzed by a 2,2′-bipyridine zinc(II) based hierarchical meso/microporous polymer, Bp-Zn@MA. Bp-Zn@MA, constructed via a template-free polycondensation reaction without using any catalyst, can efficiently catalyze the cycloaddition of propylene oxide with a TOF of up to 1580 h⁻¹ (100 °C) and 8041 h⁻¹ (150 °C), using diluted gas and pure CO₂, respectively. This is among the best performing solid catalysts ever reported for the CO₂ cycloaddition reaction. The high catalytic activity of the polymer, especially when diluted CO₂ was employed, can be mainly attributed to its hierarchical meso/microporous structure, which contains mesopores for facilitating the diffusion of reactants and micropores for CO₂ enrichment. The construction of this hierarchical structured porous material provides an efficient approach for realizing CO₂ conversion using flue gas as a feedstock.