碳材料孔径分布NLDFT研究最新进展：O2@77K模型

近日，美国麦克仪器公司首席科学家Jeffrey Kenvin博士与资深科学家Jacek Jagiello博士在Journal of Colloid and Interface Science期刊上共同发表了题为Consistency of carbon nanopore characteristics derived from adsorption of simple gases and 2D-NLDFT Models. Advantages of using adsorption isotherms of oxygen (O₂) at 77K的文章。

在本文的研究中，作者尝试采用O₂来进行气体吸附，因为据相关研究报道，O₂的四极矩值小于N₂的三分之一，因此其与极性基团的特定相互作用远小于N₂。为了验证此结论，选用4种典型的多孔碳，分别测在77k和87K下的O₂和N₂吸附，得到孔径分布（PSD）与上述结论相一致。本文中PSD（孔径分布）计算采用了2D-NLDFT吸附模型。

该文章的摘要如下：

The pore size distribution (PSD) of porous carbons is most often derived from the analysis of standard N₂ and Ar adsorption isotherms measured at 77 and 87?K. From the two gases, Ar is recommended (IUPAC Technical Report 2015) as more reliable for the PSD analysis due to its minimal specific interactions with the surface polar groups. Such interactions may influence the adsorption of N₂molecules due to its significant quadrupole moment. In practice, however, using liquid Ar as a cryogen for Ar adsorption measurements may be challenging because of its high cost and limited availability in various parts of the world. In this study, we propose using O₂ adsorption isotherms for the PSD characterization of porous carbons. The quadrupole moment of O₂ is less than one-third of the value reported for N₂, and thus its susceptibility to specific interactions with polar groups is much smaller than that of N₂. We demonstrate a quantitative agreement between the PSD results derived from the adsorption isotherms of O₂ and N₂ measured at 77K, and Ar at 87K on four representative carbon samples. The PSD calculations are performed using adsorption models based on the two-dimensional non-local density functional theory (2D-NLDFT).