大学化学 >> 2022, Vol. 37 >> Issue (1): 2104049.doi: 10.3866/PKU.DXHX202104049

师生笔谈 上一篇    下一篇

对BET方程中C的探讨

张伟庆, 黄滨, 胡谷平()   

  • 收稿日期:2021-04-23 录用日期:2021-07-02 发布日期:2021-07-12
  • 通讯作者: 胡谷平 E-mail:huguping@msil.sysu.edu.cn
  • 作者简介:胡谷平,Email: huguping@msil.sysu.edu.cn

Discussion on C in BET Equation

Weiqing Zhang, Bin Huang, Guping Hu()   

  • Received:2021-04-23 Accepted:2021-07-02 Published:2021-07-12
  • Contact: Guping Hu E-mail:huguping@msil.sysu.edu.cn

摘要:

从动力学和统计热力学角度介绍了BET方程中C的物理意义,分析了C的大小对吸附等温线形状的影响,推导了吸附等温线上拐点、B点位置和C大小的关系以及达到单程吸附量时C与相对压力、覆盖表面分数的关系。文章用数学方法介绍了保证C为正值的方法,解释了数据分析中的一个常见现象,还从BET方程的数学形式及物理意义探讨了C的下限。

关键词: BET方程, 吸附等温线, 拐点

Abstract:

In this paper, the physical meaning of C in BET equation is introduced from the view of kinetics and statistical thermodynamics. The influence of the size of C on the shape of adsorption isotherm is analyzed. The relationship between the inflection point, the position of B point and the size of C on the adsorption isotherm is deduced, and the relationship between C and relative pressure, the fraction of covered surface when the adsorption capacity reaches one-way, is also deduced. This paper introduces the method to ensure the positive value of C by mathematical method, explains a common phenomenon in data analysis, and discusses the lower limit of C from the mathematical form and physical meaning of BET equation.

Key words: BET equation, Adsorption isotherm, Inflection point

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