活性炭吸附CO_2与其微孔体积的关系

Relation between adsorption of CO_2 on activated carbon and its micropore volume

对五种活性炭样品进行液氮温度下的N2吸附、碘吸附测定和冰点下的CO2吸附表征。结果表明,碘吸附值测定法和基于N2吸附等温线的BET方程、D-R方程,孔结构参数都不能正确反映活性炭对CO2的吸附特性;由CO2吸附等温线得到的D-A模型参数也不适合分析活性炭吸附CO2特性;CO2吸附等温线的密度泛函理论(DFT)分析结果表明,CO2在活性炭上的吸附发生在极微孔内,DFT分析的微孔孔容与吸附等温线反映的吸附性能完全一致。因此,根据CO2吸附等温线的DFT模型是准确反映活性炭吸附CO2特性的表征分析方法。

Characterization of activated carbon has been carded out by N2, CO2 adsorption and iodine adsorption value. It is shown that both iodine adsorption value and pore structure parameters based on BET, D-R model for N2 adorption isotherms can not be used to reflect the adsorption property of CO2 in activated carbon. The D-A model results obtained from CO2 adsorption isotherms are not suitable for characterizing the adsorption of CO2 on activated carbon, either. The results of DFT model for CO2 adsorption isotherms showed that the adsorption of CO2 on activated carbon is in the ultramicropore. The micropore volumes from DFT model are consistent with CO2 adsorption isotherms. DFT model based on CO2 adsorption isotherms can be used to analyze the adsorption of CO2 perfectly.