Enhanced carbon dioxide conversion at ambient conditions via a pore enrichment effect

Wei Zhou,Guo-Qing Ren,Yi-Meng Li,Yi-Hong Zhou,Li Yang,Dong Zhai,Qi-Wen Deng,Lei Sun,Wei-Qiao Deng

doi:10.1038/s41467-020-18154-9

Abstract

Chemical fixation of carbon dioxide (CO2) may be a pathway to retard the current trend of rapid global warming. However, the current economic cost of chemical fixation remains high because the chemical fixation of CO2 usually requires high temperature or high pressure. The rational design of an efficient catalyst that works at ambient conditions might substantially reduce the economic cost of fixation. Here, we report the rational design of covalent organic frameworks (COFs) as efficient CO2 fixation catalysts under ambient conditions based on the finding of “pore enrichment”, which is concluded by a detailed investigation of the 10994 COFs. The best predicted COF, Zn-Salen-COF-SDU113, is synthesized, and its efficient catalytic performance for CO2 cycloaddition to terminal epoxide is confirmed with a yield of 98.2% and turnover number (TON) of 3068.9 under ambient conditions, which is comparable to the reported leading catalysts. Moreover, this COF achieves the cycloaddition of CO2 to 2,3-epoxybutane under ambient conditions among all porous materials. This work provides a strategy for designing porous catalysts in the economic fixation of carbon dioxide.

Highlights

Chemical fixation of carbon dioxide (CO2) may be a pathway to retard the current trend of rapid global warming
For our designed M-Salen-covalent organic frameworks (COFs), the embedded catalytic moieties retain the catalytic activity for CO2, and the porosity of the framework provides an environment space for gas capture
The chemical reactions are affected by the pore environment in the porous materials, such as the confinement effect

Summary

Introduction

Chemical fixation of carbon dioxide (CO2) may be a pathway to retard the current trend of rapid global warming. The best predicted COF, Zn-Salen-COF-SDU113, is synthesized, and its efficient catalytic performance for CO2 cycloaddition to terminal epoxide is confirmed with a yield of 98.2% and turnover number (TON) of 3068.9 under ambient conditions, which is comparable to the reported leading catalysts This COF achieves the cycloaddition of CO2 to 2,3-epoxybutane under ambient conditions among all porous materials. The metal-free ionic polymers have been applied in the syntheses of porous catalytic materials under the mild conditions[15,16] All these researches indicate that the incorporation of catalytic active moieties into the porous materials is a feasible way to realize the fixation CO2 under ambient conditions by achieving capture and conversion of CO2 simultaneously. The Zn-Salen-COF-SDU113 catalyst shows high catalytic activity and excellent stability and recyclability towards terminal epoxides (PO) and internal epoxides (2,3-epoxybutane) under ambient conditions

Methods

Results

Conclusion