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Multifunctional metallo‐/ionic‐covalent organic polymers (TCTB@Zn‐iCOPs) were constructed through one‐pot multicomponent reaction in a deep eutectic solvent at room temperature. The structures of various TCTB@Zn‐iCOPs were characterized, demonstrating their successful integration of multiple sites and excellent structural stability. Then TCTB@Zn‐iCOPs were employed to transform atmospheric CO2 into cyclic carbonates. The results showed that satisfactory product yields were obtained under mild and additive‐free conditions, with a high TOF value of 101 h−1; furthermore, the optimized TCTB@Zn‐iCOP2 exhibited excellent versatility in catalyzing the cycloaddition reactions between various substituted epoxides and CO2, and its activity did not significantly decrease after being reused for five times. Compared with previously reported nonmetallic iCOPs, the TCTB@Zn‐iCOP2 shows significantly improved activity and stability. Finally, DFT calculations were conducted along with a comparison of energy barriers for possible reaction paths, gaining an in‐depth understanding of the synergistic catalytic mechanism involving multiple sites. [ABSTRACT FROM AUTHOR]

Abstract: The use of supported zwitterionic nanoparticles is an interesting and important strategy for the development of new CO2 conversion catalysts with enhanced activity and selectivity. Several zwitterionic imidazole‐urea derivative frameworks bridged mesoporous hybrid silica materials were prepared and characterized by using FTIR spectroscopy, solid‐state NMR spectroscopy, X‐ray photoelectron spectroscopy, XRD, TEM, and thermogravimetric analysis. The new Im‐Si‐X‐ϕ materials possess a high surface area, hydrogen‐bond donor ability, and nucleophilicity. The material that contains iodine and is protonated by an inorganic acid shows an excellent catalytic activity for CO2 conversion into cyclic carbonates with good recyclability. Reaction parameters for the cycloaddition of CO2 with propylene oxide to propylene carbonate were optimized. The one‐component material is an efficient heterogeneous catalyst for CO2 cycloaddition reactions and is a greener alternative to conventional supported transition‐metal catalysts. Its catalytic features were also compared to those of the unsupported free ionic compound and other supported catalysts reported previously. [ABSTRACT FROM AUTHOR]

A periodic mesoporous organosilica with a basic urea-derived framework (PMO-UDF) was prepared and characterized thoroughly. The PMO-UDF showed an enhanced CO2 capture capacity at low pressure (≤1 atm) and an exceptional catalytic activity in CO2 coupling reactions with various epoxides to yield the corresponding cyclic carbonates under mild conditions because of the presence of a high surface area, basic pyridine units, and multiple hydrogen-bond donors. The highly stable catalyst could be reused at least six successive times without a significant decrease of the catalytic efficiency or structural deterioration, thus the PMO-UDF composite is considered as a promising material for CO2 capture and conversion. [ABSTRACT FROM AUTHOR]

Silver and mesoporous carbon (mC) comodified CZnO composites (Ag/mC/CZnO) were fabricated by a facile, one-step process directly from C, Ag, and Zn precursors in CO2-expanded ethanol, which provided a unique medium and did not require additional precipitant and mesoscaled organic templates. When the composite photocatalyst was applied to the degradation of rhodamine B and phenol, Ag/mC/CZnO exhibited excellent photocatalytic activity in visible light. The remarkably improved catalytic activity of the composites was attributed to the following synergistic effects. The modification of mC enriched the adsorption of pollutants on the photocatalyst. Additionally, the mesopores of carbon provided a spacious path for the separation of photogenerated electrons and holes. In addition to mC, carbon was also doped into ZnO, which narrowed the ZnO band gap. The modification of silver strengthened the absorbance of the visible region and improved the electron-trapping ability. [ABSTRACT FROM AUTHOR]

The article presents chemical equation for the article "Novel Urea Derivative-Based Ionic Liquids with Dual-Functions: CO2 Capture and Conversion under Metal- and Solvent-Free Conditions" by M. Liu and others, published in the journal "Green Chemistry" in 2016.

The introduced catalyst can be reused at least four times without significant loss of reactivity. [ABSTRACT FROM AUTHOR]

The article presents chemical equations of "Melamine-ZnI2 as Heterogeneous Catalysts for Efficient Chemical Fixation of Carbon Dioxide to Cyclic Carbonates" by M. Lui and others, published in the periodical "RSC Advances" in 2015.