Biomass-derived catalyst for CO2 cycloaddition: High efficiency and low environmental impact

The catalytic conversion of CO 2 into value-added chemicals via epoxide cycloaddition represents a promising route for sustainable carbon utilization. Herein, a facile one-pot doping strategy is developed to fabricate a robust and cost-effective catalyst from biomass waste rice husk. The N-doped carbon dots (CDs) are in situ synthesized and simultaneously doped within a mesoporous silica network via covalent C-O-Si bonds, followed by Cu(II) ions coordinating doping. The incorporation of hydrogen bond donor (such as hydroxyl groups) and Lewis base sites (nitrogen groups) on the CDs within the silica network synergistically activate the epoxides and CO 2 molecules, meanwhile the Si O protective layer promotes the catalytic stability. Furthermore, density functional theory (DFT) calculations reveal that Cu N complexes lower the energy barrier by facilitating epoxide activation. The resulting multi-confined catalyst delivers a 99% yield within 15 h at 80 °C and 1 atm CO 2 , retaining its activity after ten cycles. Life cycle and techno-economic analyses reveal that the prepared catalyst produces less CO 2 emissions and reduces the cost of styrene carbonate production to $31.3 per kg, below the commercial value ($100 per kg). This work paves a new way for sustainable and economical CO 2 valorization via highly efficient and stable catalyst.