Boulet Pascal, Narasimhan L, Berg'e-Lefranc David, Kuchta Bogdan, Schäf Oliver, Denoyel Renaud
Laboratoire Chimie Provence, University Aix-Marseille I, II and III, UMR-CNRS 6264, Avenue Escadrille Normandie-Niemen, F-13397 Marseille, France.
J Mol Model. 2009 Jun;15(6):573-9. doi: 10.1007/s00894-008-0417-6. Epub 2009 Jan 8.
Adsorption of paracresol and water into the silicalite-1 (MFI) zeolite has been investigated using canonical and grand-canonical Monte Carlo simulations. The most stable sites of adsorption of paracresol are found to be located at the channel intersections. Grand-canonical simulations have shown that at low loading, water molecules adsorb preferably at the vicinity of paracresol molecules, whereas they are also located in the sinusoidal channels as the loading increases. In order to explain the experimental adsorption isotherm observed for the coadsorption of water and paracresol in the MFI zeolite we propose a new concept of apparent adsorption enthalpy that varies with the concentration of the solution. The mathematical expression for the apparent enthalpy is introduced in an adsorption isotherm model. We shall refer to this theoretical isotherm as a non-langmuirian isotherm. The non-linear expression for the apparent adsorption enthalpy accounts for a variable accessibility of the sites of adsorption with respect to the concentration of the solution.
已使用正则系综和巨正则系综蒙特卡罗模拟研究了对甲酚和水在硅沸石-1（MFI）沸石中的吸附情况。发现对甲酚最稳定的吸附位点位于通道交叉处。巨正则系综模拟表明，在低负载量下，水分子优先吸附在对甲酚分子附近，而随着负载量增加，它们也会位于正弦形通道中。为了解释在MFI沸石中观察到的水和对甲酚共吸附的实验吸附等温线，我们提出了一个随溶液浓度变化的表观吸附焓新概念。在吸附等温线模型中引入了表观焓的数学表达式。我们将把这个理论等温线称为非朗缪尔等温线。表观吸附焓的非线性表达式解释了吸附位点相对于溶液浓度的可变可达性。
