学术论文

      微分吸附加和法计算多孔材料的吸附特性

      Determination of adsorption characteristics for porous materials from the derivative isotherm summation method

      摘要:
      采用微分吸附加和法对4种具有代表性和独特孔结构的多孔材料MIL-101、活性炭、SBA-15和NaX分子筛的N2吸附等温线的一阶导数进行拟合.吸附位点方程采用带有吸附质分子相互作用力的Dubinin-Asthakov(DA)、Langmuir和Brunauer-Emmett-Teller (BET)方程.结果表明:微分吸附加和法求取的比表面积和BET、I点法一致.与BET理论相比,该方法考虑了多孔材料表面位点不均匀、吸附质分子间存在相互作用力等因素.拟合结果揭示多孔材料表面存在不同的吸附区域,每个吸附区域存在吸附质与吸附剂作用力不同的吸附位点,而且吸附质分子间的相互作用力不能忽略.此外拟合结果也揭示了导数拟合可以作为对普通吸附等温线的新的拟合途径.
      Abstract:
      The derivative isotherms of the nitrogen adsorption data on four typical,representative porous materials,MIL-101,an activated carbon,SBA-15 and NaX zeolite were fitted by the derivative isotherm summation (DIS) method with the individual isotherm types of Dubinin-Asthakov (DA),Langmuir and Brunauer-Emmett-Teller (BET) including lateral interactions.Results showed that the surface areas calculated from the DIS method were almost the same with the BET and I-point method.Comparing the adsorption mechanism with the BET model with considering surface heterogeneous information and the lateral interactions between the adsorbed molecules,the fitting results showed that the surface of porous materials had different adsorption areas,each adsorption area could be fitted by several local isotherms with different interactions between adsorbate and adsorbent,and the lateral interactions between adsorbed molecules could not be neglected.The results also suggested that they would be used as a general method for adsorption equilibrium data fitting.
      Author: YANG Kuizhi HUANG Yanfang LYU Yong DUAN Long MA Zhengfei
      作者单位: 南京工业大学 化工学院 材料化学工程国家重点实验室,江苏南京,210009
      年,卷(期): 2017, 39(3)
      分类号: TQ028.8
      在线出版日期: 2017年7月3日