Synthesis of an amide-based gel as catalyst support for conversion of carbon dioxide

Abstract

The transformation of dynamic gels into covalent gels with stability with retention of gel matrix and porosity remains a challenge. Herein, an imine gel is synthesized employing dynamic covalent chemistry and is converted into an amide gel with chemical stability by oxidizing imine linkages into amide linkages. The transformation of imine gel into amide gel under mild conditions preserves the gel matrix, and the resulting amide gel can be used for catalysis in harsh chemical environments. Combined DFT and experiments verify the feasibility of the amide gel to improve the CO₂ adsorption. Moreover, a stable silver nanoparticles-based amide Ag@amide gel catalyst is prepared via an in-situ reduction route. The Ag@amide gel catalyst shows superior catalytic activity for the transformation of CO₂ into alkynyl carboxylic acids. Ag@amide can be easily recovered and reused for 5 times without significant change in activity. This work presents a facile way from self-assembled imine gels to stable amide gels that are used for CO₂ conversion.