Highly Porous Metalloporphyrin Covalent Ionic Frameworks with Well‐Defined Cooperative Functional Groups as Excellent Catalysts for CO₂ Cycloaddition

Abstract

The development of multifunctional heterogeneous catalysts with high porosity and remarkable catalytic activity still remains a challenge. Herein, four highly porous metalloporphyrin covalent ionic frameworks (CIFs) were synthesized by coupling 5,10,15,20‐tetrakis(4‐nitrophenyl)porphyrin (TNPP) with 3,8‐diamino‐6‐phenylphenanithridine (NPPN) or 5,5′‐diamino‐2,2′‐bipyridine (NBPy) followed by ionization with bromoethane (C2H5Br) or dibromoethane (C2H4Br2) and then metalization with Zn or Co. The resulting CIFs showed high efficiency in catalyzing the cycloaddition of propylene oxide (PO) with CO2 to form propylene carbonate (PC). All of the Zn‐containing CIF catalysts were able to catalyze the cycloaddition reaction with a PC yield greater than 97 %. The TNPP/NBPy (CIF2) catalyst ionized with C2H4Br2 and metalized with Zn (Zn‐CIF2‐C2H4) exhibited the highest catalytic activity among the synthesized catalysts. The high catalytic performance of Zn‐CIF2‐C2H4 is related to its high porosity (577 m2 g−1), high Br:metal ratio (1:3.89), and excellent synergistic action between the Lewis acidic Zn sites and the nucleophilic Br− ions. Zn‐CIF2‐C2H4 is sufficiently stable that greater than 94 % PC yield could be obtained even after six cycles. In addition, Zn‐CIF2‐C2H4 could catalyze the cycloaddition of several other epoxides with CO2. These highly porous materials are promising multifunctional and efficient catalysts for industrially relevant reactions.

Covalent Organic Frameworks for Simultaneous CO2 Capture and Selective Catalytic Transformation

“…Fourier-transform infrared (FT-IR) spectra showed a C=N stretching vibration band at 1620 cm −1 , indicative of the formation of imine linkages (Figure S1). cation, COFs have been used as catalyst supports for cyclic carbonate synthesis, uid [63,64] or poly (ionic liquid)s [65], copper oxide nanoparticles [66] and ionic [67] were grafted within the frameworks of COFs that provided promising catal formance. However, it is difficult to realize substrate size for such catalytic sy reactions proceed through one-dimensional (1D) channels of COFs.…”

“…Similarly, a zinc-porphyrin COF (COF-366-Zn) also gave good cyclic carbonates yield, but the reaction needs acetonitrile as solvent and the reaction condition is still harsh (120 • C, 1.5 MPa CO 2 ) [62]. Due to pre-designability and easy-modification, COFs have been used as catalyst supports for cyclic carbonate synthesis, ionic liquid [63,64] or poly (ionic liquid)s [65], copper oxide nanoparticles [66] and ionic polymer [67] were grafted within the frameworks of COFs that provided promising catalytic performance. However, it is difficult to realize substrate size for such catalytic systems as reactions proceed through one-dimensional (1D) channels of COFs.…”

Enhancement in the active site exposure in a porphyrin-based PIL/graphene composite catalyst for the highly efficient conversion of CO2

“…S5, † the Br 3d signals observed at 67.9 eV and 70.0 eV were attributed to Br − and Br (C-Br), respectively. 53 Comparison of the intensities of these peaks revealed that bromine element in the polymer and composition generally existed in the form of Br − . Furthermore, the elemental composition was measured by EA (for C, H, and N) and ICP-OES (for Zn) for catalyst quantification of subsequent reactivity tests (Table S1 †), which was closely consistent with the theoretical values.…”

A zinc porphyrin polymer as efficient bifunctional catalyst for conversion of CO2 to cyclic carbonates

“…Most reported heterogeneous catalysts mainly possess Lewis acid sites and nucleophilic reagents always needed as cocatalyst during the catalytic process [19][20][21][22][23][24][25][26][27][28]. Recently, the bifunctional metalloporphyrins heterogeneous catalysts combining both Lewis acid and nucleophilic sites are attracting increasing attention for the CO 2 cycloaddition reaction [29][30][31][32][33][34]. In 2018, the two supported cationic Zn-porphyrin polymers ZnTPy-BIM4/CNTs-3 and SBA-Zn-TPy + PI À reported by Yang et al showed good catalytic performance in the absence of cocatalyst [30,34].…”