Tunable Transesterification of Dimethyl Carbonate with Ethanol on K₂CO₃/Al₂O₃ Catalysts: Kinetic Modeling

Abstract

The light alkyl carbonates are indispensable co-solvents of electrolytes for lithium-ion batteries. In this work, the tunable transesterification of dimethyl carbonate (DMC) with ethanol to co-produce ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) was investigated based on an efficient catalytic system with the solid alkaline catalyst. It was found that the γ-Al2O3-supported K2CO3 catalyst exhibited high activity for the transesterification reaction, with a tunable feature for the selectivities of EMC and DEC by changing the space velocity and feed ratio of DMC to ethanol at the temperature between 120 and 150 °C. According to the results of characterizations and activity tests, a synergistic mechanism was proposed. The reaction kinetic model was also established, which displayed good agreement with the experimental results.

Fine-Tuning Electron–Donor Capability in the Basic Anion of Poly(ionic liquid) Frameworks for Revolutionizing Catalytic Synthesis of Ethyl Methyl Carbonate with Both Ultrahigh Catalytic Activity and Selectivity

“…18,23 Furthermore, there was a broad peak formed by the merge of the carbonyl C�O stretching vibration peak of CDI at 1665 cm −1 and the characteristic vibration peak of the benzene ring at 1608 cm −1 , suggesting the successful coupling of Trbb, BbIm, and CDI to achieve [CPIL-CDI][Br]. 24,25 This molecular structure could also be confirmed by the SS 13 C NMR spectra in Figure 1 30 Next, to understand the interaction between the cationic bone and anions in the PILs and to figure out the effect of electron-withdrawing or electron-donating groups on the electron-donor capability of phenolate anions, the XPS technique was applied. The full survey scan of the [CPIL-CDI][Br] XPS spectrum shown in Figure 2(a) exhibited peaks 32 We noted that the amount of neutral nitrogen was very low, suggesting that the interaction between [CPIL-CDI] and [Br] was mainly through the electrostatic attraction but without the hydrogen-bonding interaction.…”

“…[Br] and its precursors were confirmed by FTIR and SS 13 C NMR. It could be seen that the characteristic peak of Trbb at 577 cm −1 referring to C−Br disappeared after the polymerization, while C−H and C�N stretching vibration peaks of the imidazole ring could be found at 3111 and 1443 cm −1 , respectively, in the FTIR spectra of [CPIL-CDI][Br] PIL (Figure 1(a)).…”

“…Fourier transform infrared (FTIR) spectroscopy was performed using a Nicolet iS50 spectrometer with a scanning range of 400−4000 cm −1 . Solid-state 13 C nuclear magnetic resonance (SS 13 C NMR) was conducted by using an AVANCE NEO 600 instrument. Thermogravimetric analysis (TGA) was conducted on an STA449F5, with a gas flow rate of 60 mL min −1 under a N 2 atmosphere and a temperature increase rate of 10 °C min −1 from room temperature to 800 °C.…”

Jet Loop Reactor-Intensified CO2 Utilization: An Efficient Strategy for the Synthesis of Ethylene Carbonate

“…17−19 It should be noted that other organic carbonates (other than PC) can be synthesized from EC via a transesterification process. 20,21 Therefore, the development of an effective procedure for the synthesis of EC is of great significance.…”

“…The continuous utilization of fossil fuels has increased the CO 2 content in the atmosphere, which has drastically changed the global climate . Therefore, great efforts, including the use of nonfossil fuels and the fixation of CO 2, have been made to reduce the net amount of anthropogenic CO 2 released into the atmosphere. , In particular, CO 2 is a robust C1-resource that can be chemically transformed into high-value-added chemicals such as alcohols, carboxylic acids, and CO 2 -based polymers. – Especially, the cycloaddition reaction of epoxides with CO 2 constitutes a straightforward route for producing cyclic carbonates in an efficient and atom-economical manner. – Ethylene carbonates (EC), which can be synthesized by the cycloaddition of ethylene oxide (EO) and CO 2 , are an important category of industrial chemicals widely used as polar solvents, chemical intermediates, and lithium-ion battery electrolytes. , The global demand for lithium-ion battery electrolytes is growing tremendously, and owing to the rapid development of the new energy industry, it has already reached over one million tons in 2022. , In this context, the demand for organic carbonates, including EC, propylene carbonate (PC), dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate, which are solvents for lithium-ion battery electrolytes, has also increased. – It should be noted that other organic carbonates (other than PC) can be synthesized from EC via a transesterification process. , Therefore, the development of an effective procedure for the synthesis of EC is of great significance.…”