N-doped hierarchically porous carbons prepared with the assistance of chemical blowing and in-situ hard template as highly efficient CO₂ adsorbents: A combined experimental and theoretical study

In the current work, we presented the synthesis of N-doped hierarchically porous carbons (NDHPCs) through chemical activation of hierarchically structured precursor derived from polyvinylpyrrolidone (PVP) and magnesium acetate tetrahydrate. Magnesium acetate tetrahydrate served as the blowing agent, and its decomposition product MgO served as the in-situ formed hard template. Combined with KHCO3 activation, the NDHPCs demonstrated a unique micro-meso-macroporous structure. Owing to the highly porous structure (1560-2545 m(2)/g) and enriched N-doping (1.48-6.31 wt%), the NDHPCs were investigated as potential CO2 adsorbents in both post-combustion capture and pre-combustion capture applications. When the adsorption temperature was 25 degrees C, the samples showed outstanding capture performances at both 1 bar (2.97-3.88 mmol/g) and 20 bar (13.24-19.89 mmol/g). The adsorption performances were further analyzed with grand canonical Monte Carlo (GCMC) simulation. Effects of various physicochemical properties on CO2 adsorption at different pressures were thus revealed with a combined experimental-theoretical approach.