PILs@ZnO with oxygen vacancies for facilitating synthesis of DMC in transesterification

PILs@ZnOx nanocatalyst was constructed via in-situ self-assembly of pyrrolium-based PILs and ZnO, featuring tailored oxygen vacancies for potentially relieving the entrainment phenomenon of reactive distillation, dual alkaline sites and unique interfacial microenvironment to facilitate transesterification. • The catalyst exhibited outstanding activity and good stability for room-temperature synthesis of DMC from CO 2 -derived cyclic carbonate, far superior to metal oxide catalyst. • Multiple characterizations combined with in-situ spectroscopy elucidated the synergistic catalysis of dual basic active sites at the catalyst interface. Pyrrolium-based polymeric ionic liquids-functionalized ZnO nanocatalysts (PILs@ZnO) with an oxygen-vacancy-enriched interface were fabricated via in-situ oxidative polymerization to resolve the entrainment phenomenon in reactive distillation process of producing DMC. The unique interfacial microenvironment effectively modulates the electronic structures and enhances the synergistic catalysis, which could lower the reaction temperature of transesterification between ethylene carbonate and dimethyl carbonate to ambient conditions, and performed the results of EC conversion with 86.7% and DMC selectivity with over than 99.0%. Physicochemical characterizations including FTIR, XRD, XPS and HRTEM were combined with in-situ FTIR and NMR to reveal the structure-activity relationship and further proposed its probably real-time catalytic process. At room temperature, the designed PILs@ZnO x catalyst behaved multiple functional active sites, including strongly basic OH - , pyrrolium-N + cations and Lewis-basic ZnO nanoparticles with a newly constructed oxygen-vacancy microelectronic interface to potentially relieve the entrainment phenomenon in reactive distillation process of producing DMC. Benefiting from the synergistic effect of these multifunctional moieties, PILs@ZnO x exhibits outstanding catalytic performance for the synthesis of DMC from cyclic carbonate. Its catalytic activity is far superior to the pristine ZnO, pure PPY + OH - , and other corresponding PILs-supported metal oxide (PPY + OH - @MgO, PPY + OH - @Al 2 O 3 , PPY + OH - @CaO and PPY + OH - @ZrO 2 ). Download: Download high-res image (327KB) Download: Download full-size image