Zwitterion π–conjugated network polymer based on guanidinium and β-ketoenol as a heterogeneous organo-catalyst for chemical fixation of CO2 into cyclic carbonates

Mousumi Garai,Zakir Ullah,Vepa Rozyyev,Cafer T Yavuz,Aqil Jamal

doi:10.1063/1.5122017

Abstract

The chemical fixation of CO2 with epoxides to cyclic carbonate is an attractive 100% atom economic reaction. It is a safe and green alternative to the route from diols and toxic phosgene. In this manuscript, we present a new zwitterionic π–conjugated catalyst (Covalent Organic Polymer, COP-213) based on guanidinium and β-ketoenol functionality, which is synthesized from triaminoguanidinium halide and β-ketoenols via the ampoule method at 120 °C. The catalyst is characterized by FTIR-attenuated total reflection (ATR), Powder X-Ray diffraction, thermogravimetric analysis, XPS, and for surface area Brunauer–Emmett–Teller and CO2 uptake. It shows quantitative conversion and selectivity in chemical fixation of CO2 to epoxides under ambient conditions and without the need for cocatalysts, metals, solvent, or pressure. The catalyst can be recycled at least three times without the loss of reactivity.

Highlights

Carbon dioxide (CO2) is one of the dominant anthropogenic greenhouse gases, which is believed to be contributing to global warming and climate change; CO2 chemistry has appealed worldwide as the most important and top priority for the scientific community.[1,2,3,4,5,6,7] Recently, the CO2 concentration increased to 415 ppm in the atmosphere and continues increasing.On the other hand, CO2, an abundant, nontoxic, cheap, and nonflammable carbon source, which is formed from living organisms and in industrial processes, is a significant resource and can be handled at an industrial level
We present a new zwitterionic π–conjugated catalyst (Covalent Organic Polymer, covalent organic polymers (COPs)-213) based on guanidinium and β-ketoenol functionality, which is synthesized from triaminoguanidinium halide and β-ketoenols via the ampoule method at 120 ○C
One of the most promising methodologies is the synthesis of five-membered cyclic carbonates via the cycloaddition reaction of CO2 to epoxides.[9,10,11,12,13,14]

Summary

Introduction

Carbon dioxide (CO2) is one of the dominant anthropogenic greenhouse gases, which is believed to be contributing to global warming and climate change; CO2 chemistry (capture and conversion) has appealed worldwide as the most important and top priority for the scientific community.[1,2,3,4,5,6,7] Recently, the CO2 concentration increased to 415 ppm in the atmosphere and continues increasing.On the other hand, CO2, an abundant, nontoxic, cheap, and nonflammable carbon source, which is formed from living organisms and in industrial processes, is a significant resource and can be handled at an industrial level. It shows quantitative conversion and selectivity in chemical fixation of CO2 to epoxides under ambient conditions and without the need for cocatalysts, metals, solvent, or pressure.

Results

Conclusion