Computational Results
The calculations in this work were performed using Forcite module in Materials Studio.17 To calculated the interaction energy between LAB isomers and zeolite, we first build a cleaved model with the bowl shape structure exposed on the surface to provide effective adsorption space. This model was optimized with energy, force, displacement convergence thresholds set to 1×10-4 kcal/mol, 5×10-3 kcal/mol/Å and 5×10-3 Å, respectively. The van der Waals interaction between the atoms was modeled using universal force field, while the electrostatic interaction was described with atomic partial charges calculated using QEq method and summed with Ewald method. The van der Waals interaction was truncated within a cutoff distance of 15.5 Å, and the Ewald accuracy for computing electrostatic interaction was set to 1×10-4 kcal/mol. After the optimization, one molecule of the LAB isomers was respectively adsorbed in the bowl shape structure of the model as an adsorbed configuration. These configurations were sequentially optimized with the same parameters as optimizing the bare model. Finally, using the same parameters to describe van der Waals interaction and electrostatic interaction, we calculated the single point energy of these adsorbed configurations, the bare adsorbent model and the LAB isomers, and obtained the binding energy using Eq.1,
Ebinding = Econfiguration - Ebare model - ELAB (1)