title: CO2-filling capacity and selectivity of carbon nanopores: synthesis, texture, and pore-size distribution from quenched-solid density functional theory (QSDFT).
abstract: Porous carbons synthesized by KOH activation of petroleum coke can have high surface areas, over 3000 m(2)/g, and high CO(2) sorption capacity, over 15 wt % at 1 bar. This makes them attractive sorbents for carbon capture from combustion flue gas. Quenched solid density functional theory (QSDFT) analysis of high-resolution nitrogen-sorption data for such materials leads to the conclusion that it is the pores smaller than 1 nm in diameter that fill with high-density CO(2) at atmospheric pressure. Upon increasing pressure, larger and larger pores are filled, up to about 4 nm at 10 bar. An ideal CO(2)/N(2) selectivity of such carbon materials tends to decrease substantially upon increasing pressure, for example, from about 8-10 at 1 bar to about 4-5 at 10 bar. All in all, this work confirms the robust CO(2)-filling properties of porous carbon sorbents, their low-pressure selectivity advantages, and points to the critical role of <1 nm pores that can be controlled with activation conditions.
authors: College of Chemistry and Life Science, Zhejiang Normal University, Jinhua, Zhejiang 321004, PR China. huxin@zjnu.edu.cn
authors: Xin
authors: X
authors: Hu
authors: Maciej
authors: M
authors: Radosz
authors: Katie A
authors: KA
authors: Cychosz
authors: Matthias
authors: M
authors: Thommes
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry; D008956:Models, Chemical; D058608:Nanopores; D009584:Nitrogen / Q000737:chemistry; D010316:Particle Size; D016062:Porosity; D017680:Potassium Compounds / Q000737:chemistry; D011789:Quantum Theory; D013499:Surface Properties; D013696:Temperature
chemical_list: D006878:Hydroxides; D017680:Potassium Compounds; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen; C029943:potassium hydroxide