State‐of‐the‐Art Aluminum Porphyrin‐based Heterogeneous Catalysts for the Chemical Fixation of CO2 into Cyclic Carbonates at Ambient Conditions

Abstract

AbstractA series of metalloporphyrin‐based hyper‐crosslinked polymers (M‐HCPs: M=Al, Co, Fe, Mn) has been directly synthesized through Friedel–Crafts alkylation reactions. The M‐HCPs afforded abundant permanent nanopores, high Brunauer–Emmett–Teller (BET) surface area, and exceptional CO2/N2 adsorptive selectivity. The experimental results suggested that the hollow tubular Al‐HCP exhibited extraordinary catalytic performance in the solvent‐free synthesis of cyclic carbonates from epoxides and CO2 by using tetrabutylammonium bromide as a cocatalyst under mild conditions, which was clearly superior to the corresponding homogeneous analogue. Surprisingly, a high turnover frequency (TOF) value of 14 880 h−1 was achieved with propylene oxide at 100 °C and 3.0 MPa, which was a promising result for industrial production compared with previously reported heterogeneous catalysts. More interestingly, Al‐HCP could smoothly catalyze the cycloaddition reaction, producing the corresponding cyclic carbonates by using simulated flue gas (15 % CO2 and 85 % N2 in volume) as the raw material under ambient conditions. Moreover, Al‐HCP could be readily recycled and efficiently reused more than ten times, exhibiting excellent stability.