Development of High Yielded Sn-Doped Porous Carbons for Selective CO2 Capture

The use of porous carbons for selective CO2 separation attracts increasing attention. Owing to low thermostability of porous polymers, low yield is the major concern of porous carbons. To obtain porous carbons with high yield, the development of thermostable porous polymers is highly expected. Herein, high yielded (70% for 700 °C and 64% for 800 °C) Sn-doped porous carbons (SnPCs) have been constructed through KOH-assisted carbonization of Sn-containing polymer. Notably, SnPC-700 (218.5 mg·g–1) demonstrates higher CO2 adsorption capacity than the reference sample prepared without KOH, SnPC-700r (188.3 mg·g–1), indicating the importance of KOH-assisted activation. Carbonization temperature has an effect on the adsorption capacity of resultant materials, and high carbonization temperature leads to better adsorption capacity on CO2. SnPC-800 is able to capture 242.8 mg·g–1 of CO2, which is better than some benchmarks including BILP-7 (193.0 mg·g–1), PAF-1–450 (196.4 mg·g–1), and FCTF-1 (205.5 mg·g–1). More importantly, SnPC-800 demonstrates good selectivity of CO2 over CH4 (31.1). Thus, high yield and good performance upon CO2 adsorption capacity and selectivity over CH4 make SnPCs attractive candidates for the removal of CO2 from natural gas.