LAUSR

Abstract Herein, octaphenylcyclotetrasiloxane was used as the substrate, cyanuric chloride was applied as the cross-linker, and a series of novel hyper-cross-linked polymers with organic-inorganic hybrid framework and spherical morphology was fabricated by a typical Friedel-Crafts reaction. These polymers were used as the excellent precursors for the synthesis of N-doped porous carbons. After KOH-activation carbonization, the spherical morphology of the polymers was retained while the porosity was significantly enhanced. Interestingly, the Brunauer-Emmett-Teller surface area (SBET), total pore volume (Vtotal), micropore volume (Vmicro), and Vmicro/Vtotal of the carbons could be finely tuned in the range of 237–2058 m2/g, 0.12–1.08 cm3/g, 0.10–0.93 cm3/g, and 79.4–88.5%, respectively, and the microporosity was distinctly improved as the carbonization temperature increased. These carbons owned decent CO2 uptake (80–263 mg/g), HCP2b-K700 had the highest CO2 uptake of 263 mg/g at 273 K and 1.0 bar and it arrived at 590 mg/g at 298 K and 10 bar. These carbons had moderate isosteric heat of adsorption (20.3–41.8 kJ/mol) and acceptable CO2/N2 selectivity (IAST: 10.8–43.7). The porous carbons developed therein had high surface area and outstanding microporosity, endowed them with promising application prospect in CO2 capture and sequestration.