N-doped Porous Carbon Derived from the Pyrolysis of a Polydopamine-coated Hypercross-linked Polymer for Enhanced CO₂ Adsorption

Porous carbon materials can simultaneously capture and convert carbon dioxide, helping to reduce greenhouse gas emissions and using carbon dioxide as a feedstock for the production of valuable chemicals or fuel. In this work, a series of N-doped porous carbons (PDA@HCP(x:y)-T) was prepared; the CO₂ adsorption capacity of the prepared PDA@HCP(x:y)-T was enhanced by coating polydopamine (PDA) on a hypercross-linked polymer (HCP) and then adjusting the mass ratio of PDA to HCP and the carbonization temperature. The results showed that the prepared PDA@HCP(1 : 1)-850 exhibited a high CO₂ adsorption capacity due to abundant micropores (0.6762 cm³/g), a high specific surface area (1220.8 m²/g), and moderate surface nitrogen content (2.75 %). Notably, PDA@HCP(1 : 1)-850 exhibited the highest CO₂ uptake of 6.46 mmol/g at 0 °C and 101 kPa. Critically, these N-doped porous carbons can also be used as catalysts for the reaction of CO₂ with epichlorohydrin to form chloropropylene carbonate, with chloropropylene carbonate yielding up to 64 % and selectivity of the reaction reaching 94 %. As a result, these N-doped porous carbons could serve as potential candidates for CO₂ capture and conversion due to their high reactivity, excellent CO₂ uptake, and good catalytic performance.