Achieving the Transformation of Captured CO2 to Cyclic Carbonates Catalyzed by a Bipyridine Copper Complex-Intercalated Porous Organic Framework

Environmentally sustainable synthesis of cyclic carbonates from epoxides and CO2 promoted by MCM-41 supported dual imidazolium ionic liquids catalysts

A type of MCM-41 supported dual imidazolium ionic liquids have been synthesized and efficiently used as catalysts in the sustainable chemical conversion of CO2 and epoxides into cyclic carbonates. It was shown that the highest efficiency was achieved in the cycloaddition of a variety of epoxides and CO2 in the presence of the MCM-41@DILSCN solid catalyst under mild conditions. More interestingly, the catalyst was stable, very active, robust, and displayed good recyclability without significant loss of catalytic activity after six consecutive cycles during the process. Overall, the present protocol of synthesizing cyclic carbonates under solvent free conditions using MCM-41@DILSCN is promising for industrial applications.

The Al(iii)-based polydentate chelate complex catalyzed cycloaddition of carbon dioxide and epoxides: synthetic optimization and mechanistic study

Aimed at greenhouse gas CO2 high value-added utilization, a N,N′-(propane-1,3-diyl)dipicolinamide (PPPA) supported Al(iii) metal–organic polydentate chelate complex (Al-PPPA) was designed and used to efficiently catalyze CO2 to cyclic carbonates.

Metal-assisted synthesis of salen-based porous organic polymer for highly efficient fixation of CO2 into cyclic carbonates

A series of metal–salen-based porous organic polymers was synthesized using a simple metal-assisted synthetic method, among which Co-salen-POP exhibited highly efficient performance in the fixation of CO2 into cyclic carbonates.

Synthesis of Sulfonated Porous Organic Polymers with a Hydrophobic Core for Efficient Acidic Catalysis in Organic Transformations

Synthesis of sulfonated porous polymers with improved hydrophobicity and stability is of extreme importance in both academic research and industrial applications. However, there is often a trade-off between acidity and surface hydrophobicity of sulfonated polymers. In this study, we report a strategy for the synthesis of sulfonated porous organic polymers (S-PT) with improved hydrophobicity via free radical polymerization method by using a rigid and large multidentate monomer, 1,3,5-tri(4-vinylphenyl)-benzene, having a hydrophobic core. The results of vapor adsorption measurement show that S-PT has more hydrophobic properties than sulfonated poly(divinylbenzene) (S-PD), attributed to the hydrophobic core of its multidentate monomer. Furthermore, the optimization of sulfonation time established a balance between surface acidity and hydrophobicity. Under optimized conditions, S-PT afforded up to 113 mmol g^-1  h^-1 TOF in the esterification of oleic acid with methanol, more active than commercial Amberlyst-15 with TOF of 15 mmol g^-1  h^-1 and Nafion NR50 with TOF of 7 mmol g^-1  h^-1 . We believe that the findings of this study will provide useful insights to advance the design and synthesis of solid acid catalysts for organic transformations.

Synthesis of Bifunctional Porphyrin Polymers for Catalytic Conversion of Dilute CO2 to Cyclic Carbonates

Development of efficient solid catalysts for catalytic conversion of dilute CO2 is of extreme importance for carbon capture and utilization. We report the synthesis of bifunctional polymers co-incorporated with porphyrin-Zn as Lewis acid sites and Br- as nucleophiles for the cycloaddition of dilute CO2 with epoxides in this work. It was found that the Br-/Zn ratio has a volcano relation with the activity of bifunctional polymers in a cycloaddition reaction, indicating the synergy effect between Lewis acid sites and nucleophiles. The turnover frequency (TOF) of the bifunctional polymer is more than four-fold that of the physical mixture of tetrabutylammonium bromide and porphyrin-Zn-incorporated polymer, implying the enhanced cooperation between Br- and porphyrin-Zn in the polymer network. The bifunctional polymer with optimized Br-/Zn afforded 99% conversion, 99% selectivity, and a TOF as high as 12,000 h-1 for the cycloaddition of CO2 and propylene oxide, which is among the most active solid catalysts ever reported. Furthermore, the bifunctional polymer could efficiently catalyze the cycloaddition of epichlorohydrin with dilute CO2 (7.5% CO2 balanced by N2) even under ambient conditions, demonstrating its potential application in industrial-scale production.

Highly active ultrafine Pd NPs confined in imine-linked COFs for nitrobenzene hydrogenation

Ultrafine Pd NPs with an average size of 1.8 nm were stabilized on an imine-linked COF. The Pd/COF with electron rich surface properties and a high surface area showed high catalytic activity in the hydrogenation of nitrobenzene.