In this work, zirconium-based metal-organic framework Zr-MOF-808-P has been found to be an efficient and versatile catalyst for amide esterification. Comparing with previously reported homogeneous and heterogeneous catalysts, Zr-MOF-808-P can promote the reaction for a wide range of primary, secondary and tertiary amides with n-butanol as nucleophilic agent. Different alcohols have been employed in amide esterification with quantitative yields. Moreover, the catalyst acts as a heterogeneous catalyst and could be reused for at least five consecutive cycles. The amide esterification mechanism has been studied on the Zr-MOF-808 at molecular level by in situ FTIR spectroscopic technique and kinetic study.

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Zr-MOF-808 as Catalyst for Amide Esterification

Kinetics for the biodiesel production from lauric acid over Keggin heteropolyacid loaded in silica framework

Novel and facilely prepared 2-pyridinamide-functionalized ionic liquids 1–4 (PAIL1–4) were explored for the cycloaddition reaction of carbon dioxide with various epoxides to generate cyclic carbonates. The optimum temperature, CO2 pressure, and catalyst dosage of the cycloaddition reaction, are 60 °C, 0.5 MPa, and 5 mol% respectively. The synthesized N, N-dimethyl-N-(2-oxo-2-(pyridin-2-ylamino)ethyl)butan-1-aminium iodide (PAIL-3) exhibited brilliant catalytic activities under mild conditions with nearly quantitative selectivity and conversion in the absence of any solvents, or metal co-catalysts. The catalyst PAIL-3 could be recycled 4 times without obvious loss of its catalytic activity. Moreover, a plausible mechanism is proposed based on the NMR experiments. The designed pyridinamide functionalized ionic liquids integrated pyridine unit, halogen anion and the N-H moiety in amide and they have an excellent synergistic catalytic effect in promoting the coupling reactions of carbon dioxide and epoxides. 

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Design and synthesis of pyridinamide functionalized ionic liquids for efficient conversion of carbon dioxide into cyclic carbonates

The development of heterogeneous catalysts for promoting epoxide cycloaddition with carbon dioxide is highly desirable for recycling CO2 and achieving the goal of carbon neutrality. Herein, we designed and synthesized...

Guanidyl-implanted UiO-66 as efficient catalysts for enhanced conversion of carbon dioxide into cyclic carbonates

Recent knowledge in chemistry has enabled the material utilization of greenhouse gas (CO2) for the production of organic carbonates using mild reaction conditions. Organic carbonates, especially cyclic carbonates, are applicable as green solvents, electrolytes in batteries, feedstock for fine chemicals and monomers for polycarbonate production. This review summarizes new developments in the ring opening of epoxides with subsequent CO2-based formation of cyclic carbonates. The review highlights recent and major developments for sustainable CO2 conversion from 2000 to the end of 2021 abstracted by Web of Science. The syntheses of epoxides, especially from bio-based raw materials, will be summarized, such as the types of raw material (vegetable oils or their esters) and the reaction conditions. The aim of this review is also to summarize and to compare the types of homogeneous non-metallic catalysts. The three reaction mechanisms for cyclic carbonate formation are presented, namely activation of the epoxide ring, CO2 activation and dual activation. Usually most effective catalysts described in the literature consist of powerful sources of nucleophile such as onium salt, of hydrogen bond donors and of tertiary amines used to combine epoxide activation for facile epoxide ring opening and CO2 activation for the subsequent smooth addition reaction and ring closure. The most active catalytic systems are capable of activating even internal epoxides such as epoxidized unsaturated fatty acid derivatives for the cycloaddition of CO2 under relatively mild conditions. In case of terminal epoxides such as epichlorohydrin, the effective utilization of diluted sources of CO2 such as flue gas is possible using the most active organocatalysts even at ambient pressure.

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Utilization of CO2-Available Organocatalysts for Reactions with Industrially Important Epoxides

Esterification kinetics on acetic acid with isopropyl alcohol was studied in an intensified fixed bed reactor at 333-353 K with Amberlyst 36 Wet. The effects of volume flow rate, molar ratio of reactants, catalyst loading, and operating temperature were investigated and optimized. The method of UNIFAC was applied to calculate the activity coefficient of each component for correcting the nonideality of the solution. Reaction enthalpy, entropy, and Gibbs free energy were calculated in different cases. The pseudohomogeneous model, Eley-Rideal model, and Langmuir-Hinshelwood-Hougen-Watson model were used to establish kinetic equations of the reaction conducted in the IFBR. It was proved that the LHHW model can accurately describe the esterification kinetics in the intensified fixed bed reactor.

Kinetic Study on Esterification of Acetic Acid with Isopropyl Alcohol Catalyzed by Ion Exchange Resin.

Novel imidazolium-based deep eutectic solvents were facilely synthesized and characterized by TGA, DSC, FT-IR, and NMR techniques. Various imidazolium salts and aromatic compounds containing active hydrogens were applied as HBAs and HBDs respectively for efficient cycloaddition of CO2 with styrene oxide under ambient conditions. The optimized [C1C2Im]I/m-DHB (1-ethyl-3-methylimidazolium iodide/m-dihydroxybenzene) DES with the molar ratio of 2:1 exhibited excellent catalytic activity at room temperature and 0.1 MPa CO2 pressure without cocatalyst, metal, and solvent. Moreover, the effects of reaction parameters, substrate scope, and catalyst recovery were studied in detail. Based on the results, the plausible reaction mechanism on the multisite synergistic activation of the epoxide by the hydrogen bonds involved with both the OH in m-DHB and C2-H in [C1C2Im]I was proposed. Finally, the reaction kinetics was studied and the cycloaddition reaction was accorded with the pseudo-first-order reaction kinetic model.

Imidazolium-based deep eutectic solvents as multifunctional catalysts for multisite synergistic activation of epoxides and ambient synthesis of cyclic carbonates

Kinetics and thermodynamics of esterification by a cation-exchange resin in an intensified fixed-bed reactor was studied systematically. The resin type, catalyst loading, volume flow rate, initial ...

Aidong Zhou

Papers

Kinetic Study on Esterification of Acetic Acid with Isopropyl Alcohol Catalyzed by Ion Exchange Resin.

Imidazolium-based deep eutectic solvents as multifunctional catalysts for multisite synergistic activation of epoxides and ambient synthesis of cyclic carbonates

Thermodynamic and Kinetic Study on the Catalysis of Isoamyl Acetate by a Cation-Exchange Resin in an Intensified Fixed-Bed Reactor.