煤基多孔碳分子筛的孔结构特征

The study of structural characterization of carbon molecular sieve based on coal

碳分子筛(CMS)的吸附分离性能主要取决于比表面积和孔径分布结构,在不同相对压力下的吸附行为对应不同的孔径分布结构。以N_2吸附等温线为依据,采用BET法计算比表面积,H-K方程模型表征微孔结构,运用D-A方程模型表征微孔比表面积、微孔体积等相关信息,密度函数理论表征全孔分布。结果表明,糠醇吸附时间达到18 h时,碳分子筛的微孔面积为最大,占到BET比表面积的98.9%。同时发现D-A方程和H-K方程模型表征微孔的局限性要在密度函数理论的分析下才能很好的互补。

The adsorptive capacity of carbon molecular sieve(CMS)mainly depends on the specific surface area and porous structure,moreover,the adsorption at different relative pressure matches with different pore size distribution structure.The microstructure and adsorptive capacity of CMS with different specific surface area was systematically investigated employing N 2 adsorption isotherm.The specific surface area of samples was calculated from the BET method,the micropore surface area,micropore volume was obtained from Dubinin-Astakhov and Horvath-Kawazoe method,the pore distribution was further characterized by density functional theory.According to research,the micropore surface area of CMS is the largest,accounting for 98.9%of BET specific surface area,when furfuryl alcohol adsorption time was 18 h.The limitations of Dubinin-Astakhov and Horvath-Kawazoe equation model characterization of microporous was remedied by the density function theory.