Importance of pore length and geometry in the adsorption/desorption process: a molecular simulation study

TL;DR

This study demonstrates that the three-dimensional Ising model effectively simulates gas adsorption/desorption in mesoporous systems, accurately capturing pore length and geometry effects with significant computational efficiency.

Contribution

It introduces the use of the 3D Ising model for simulating adsorption in complex pore geometries, offering a faster alternative to traditional molecular simulations.

Findings

Excellent agreement with experimental hysteresis loop areas.

Pore length significantly influences hysteresis behavior.

The model accurately predicts adsorption/desorption phenomena.

Abstract

Discrete potentials can describe properly the liquid vapor boundary that is necessary to model the adsorption of gas molecules in mesoporous systems with computer simulations. Although there are some works in this subject, the simulations are still highly time - consuming. Here we show that an efficient alternative is to use the three - dimensional Ising model, which allows one to model large systems, with geometries as complex as required that accurately represent the liquid vapor boundary. In particular, we report molecular simulations of cylindrical pores of two different geometry, using a discrete potential. The effect of the length of the pore in the hysteresis loop for a finite pore and infinite one is studied in detail. Lastly, we compare our predictions with experimental results and find excellent agreement between the area of the hysteresis loop predicted for the finite pore and that found in adsorption/desorption experiments.