An Efficient and Super Stable Immobilized Ionic Liquid Catalyst Application in the Catalytic Synthesis of Carbonates

Abstract

Homogeneous catalysts suffer from difficulty in product separation and recycling. To solve these problems, a strong basicity immobilized ionic liquid catalyst (PS-IMC4IM) was constructed. Various characterizations were applied to identify the differences in the structure and active components of the catalyst during the preparation process and with the spent catalyst. The results indicated that a bis-imidazole ionic liquid (IMC4IM) was successfully immobilized on the polystyrene resin (PS) by covalent bonding. The basic amount of PS-IMC4IM was 0.84 mmol/g, and its basic strength was 9.8 < H_ < 12.8. Its structure and the number of active components remained unchanged after 2000 h of reaction. PS-IMC4IM displayed an admirable catalytic performance in the transesterification of ethylene carbonate (EC) and methanol (MeOH) to synthesize dimethyl carbonate (DMC) at a mild reaction condition. The EC conversion was 76.9%, and the turnover frequency (TOF) was 12.5 h–1 in a fixed-bed reactor. What is more, the TOF value was raised to 76.7 h–1 in the slurry phase reactor. Compared with other reported catalysts, PS-IMC4IM exhibited excellent catalytic ability and stability. Besides, PS-IMC4IM has the capability to synthesize a series of carbonates via transesterification, including diethyl carbonate (DEC), methyl ethyl carbonate (EMC), and glycerol carbonate (GLC). PS-IMC4IM provides a new method to develop highly efficient and stable heterogeneous catalysts for transesterification reactions.

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.…”

Application of Mesoporous Carbon-Based Highly Dispersed K–O2 Strong Lewis Base in the Efficient Catalysis of Methanol and Ethylene Carbonate

“…Although metal-free heterogeneous catalysts, such as g-C 3 N 4 , can be used in the transesterification reaction of CH 3 OH with EC, the whole reaction system requires high reaction pressures/temperatures and long reaction times and the selectivity of g-C 3 N 4 to the product is low. In contrast, metal-containing heterogeneous catalysts (e.g., NaZSM, CeO 2 , Cu–Zn–Al, Ce-M ( M = Cu, Fe, Co), CeO 2 /ZnO, SrO/CeO 2 , Ca 3 Co 4 O 9 , PS-IMC4IM, CeO 2 nanoparticles, La 2 O 3 , and Ce/La 2 O 2 CO 3 ) perform favorably in transesterification reaction of CH 3 OH with EC because they have a higher abundance of basic sites compared with metal-free heterogeneous catalysts. However, the agglomeration of active species is still a pressing issue for metal-containing heterogeneous catalysts.…”