Fixation of CO2 as carboxylic acid catalyzed by acetylglucosyl 2-methyl-imidazolium and AuNP-modified polyacrylonitrile fiber

Abstract

The development of sustainable methods for converting CO₂ into valuable chemicals under mild conditions is essential for addressing climate change and advancing a circular carbon economy. However, current approaches often face limitations such as harsh reaction conditions, low catalyst efficiency, and poor recyclability. Inspired by the CO₂-capturing capability of polysaccharides and imidazolium-based ionic liquids, we developed a novel heterogeneous catalyst PAN_AMI-Au⁰F. This functionalized polyacrylonitrile fiber was synthesized by grafting imidazolium ionic liquids, comprising acetylglucosyl and methyl 4-[(2-methyl-1H-imidazol-1-yl)methyl]benzoate, onto the fiber surface, followed by coordination with gold nanoparticles. Owing to strong CO₂ enrichment capability, the PAN_AMI-Au⁰F catalyst exhibits excellent activity in the carboxylation of phenylacetylene with atmospheric CO₂, delivering a high yield of 98% under mild conditions (0.5 mol% catalyst, 50 °C, 10  h, 1 atm CO₂). Notably, the catalyst maintains a high yield of 91% after five consecutive catalytic cycles and achieves 90% yield in gram-scale synthesis. Overall, PAN_AMI-Au⁰F provides a mild, efficient, and recyclable catalytic system for the sustainable conversion of CO₂ from exhaust gases into value-added chemicals.