Abstract
CO2 is an important by-product in epoxides synthesis, accounting for 0.02% of worldwide greenhouse emissions. The CO2 cycloaddition to ethylene and propylene oxides is an important class of reactions due to the versatile nature of the corresponding organic carbonates as chemical feedstocks. We report that these reactions can be catalyzed by ZIF-8 (Zeolitic Imidazole Framework-8) in the absence of solvent or co-catalyst and in mild conditions (40 °C and 750 mbar). In situ infrared spectroscopy places the onset time for ethylene and propylene carbonate formation to 80 and 30 min, respectively. Although there is low catalytic activity, these findings suggest the possibility to cut the CO2 emissions from epoxides production through their direct conversion to these highly valuable chemical intermediates, eliminating de facto energetically demanding steps as the CO2 capture and storage.
Highlights
Strategies for the mitigation of climate change effects require the implementation of processes aimed to attenuate anthropogenic CO2 emissions, estimated to 36.2 Gt year−1, in 2015 [1]
We showed that ZIF-8 catalyzes the CO2 cycloaddition to EtO and to PrO with a very similar behavior
This study has shown that the commercially available MOF ZIF-8 is able to catalyze EtO and PrO carbonation to ethylene carbonate (EtC) and propylene carbonate (PrC), respectively
Summary
Strategies for the mitigation of climate change effects require the implementation of processes aimed to attenuate anthropogenic CO2 emissions, estimated to 36.2 Gt year−1, in 2015 [1]. Most of them require a high purity CO2, further increasing the cost of the separation process [5,8] In this view, the advantages to coupling in a single step the separation and recycling of CO2 are evident [9,10]. Cyclic organic carbonates are important solvents and chemical reagents [11]. Their traditional synthesis involves phosgene, with consequent concerns on safety. A green alternative protocol considers the cycloaddition of CO2 to oxiranes [5,12] that allows the production of organic carbonates, in monomeric (see Scheme 1) or polymeric form [13,14], with the advantages of safer reagents and of the CO2 reuse. An 8% in volume of CO2 is produced in the synthesis of ethylene
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
