Computational screening of structure directing agents for the synthesis of zeolites. A simplified model

Abstract

Zeolite micropores become more energetically stable by the occlusion of organic structure directing agents (templates). This energetic stabilisation, if approximated by van der Waals zeo-template interactions, can be calculated in a fast way by using modern computing techniques incorporating big data handling algorithms for massive screening. A software suite is presented which calculates an arbitrarily large 2-D matrix (template×zeolite) giving the zeo-template van der Waals interaction energy corresponding to the minimum energy conformation assuming one template molecule in a pure silica zeolite unit cell. With the goal of simplicity, the software only needs two coordinate input files of template and zeolite unit cell. Though a number of approximations have been considered, the software allows to compare, for a given template, which competing zeolite phases may become more stabilised. Applied to zeolite hypothetical databases, it may be of help to suggest templates for their synthesis.

Simulation-based evaluation of zeolite adsorbents for the removal of emerging contaminants

“…This fit can be predicted reasonably well using the simple vdW-only picture employed, as has been done previously in computational studies of the stabilisation of zeolite frameworks by OSDAs. [52][53][54][55][56][57][58] As a consequence, it appears that the interaction energy E zg could be used in a predictive fashion to identify adsorbents with a high affinity towards a given pollutant. However, it needs to be re-emphasised that the zeolite-guest interaction energy is an artificial quantity that has no directly measurable experimental analogue, and that any simulation approach aiming at a physically accurate description of the actual adsorption process would necessarily have to be much more complex.…”

“…In the view of the widespread use of computational chemistry methods in zeolite science, 43,44 this appears somewhat surprising. In the field of molecular mechanics calculations, force-field based Monte Carlo (MC) and molecular dynamics (MD) simulations have been employed to study the adsorption and/or diffusion of organic molecules in all-silica zeolites for several species of considerable complexity, including substituted aromatics, [45][46][47][48][49][50][51] organic structure-directing agents (OSDAs), [52][53][54][55][56][57][58] and glucose. 59 In contrast to this, applications of force field methods to study the interaction of pharmaceuticals with zeolites are scarce, with the MD investigation of salbutamol and theophylline diffusion in zeolite beta by Fatouros et al being a rare example.…”

Simulation-Based Evaluation of Zeolite Adsorbents for the Removal of Emerging Contaminants

“…This fit can be predicted reasonably well using the simple vdW-only picture employed, as has been done previously in computational studies of the stabilisation of zeolite frameworks by OSDAs. [51][52][53][54][55][56][57] As a consequence, it appears that the interaction energy E zg could be used in a predictive fashion to identify adsorbents with a high affinity towards a given pollutant. However, it needs to be emphasised that the zeolite-guest interaction energy is an artificial quantity that has no directly measurable experimental analogue, and that any simulation approach aiming at a physically accurate description of the actual adsorption process would necessarily have to be much more complex.…”

“…In the view of the widespread use of computational chemistry methods in zeolite science, [43,44] this appears somewhat surprising. In the field of molecular mechanics calculations, force-field based Monte Carlo (MC) and molecular dynamics (MD) simulations have been employed to study the adsorption and/or diffusion of organic molecules in all-silica zeolites for several species of considerable complexity, including substituted aromatics, [45][46][47][48][49][50] organic structure-directing agents (OSDAs), [51][52][53][54][55][56][57] and glucose. [58] In contrast to this, applications of force field methods to study the interaction of pharmaceuticals with zeolites are scarce, with the MD investigation of salbutamol and theophylline diffusion in zeolite beta by Fatouros et al being a rare example.…”

Simulation-Based Evaluation of Zeolite Adsorbents for the Removal of Emerging Contaminants

“…This fit can be predicted reasonably well using the simple vdW-only picture employed, as has been done previously in computational studies of the stabilisation of zeolite frameworks by OSDAs. [52][53][54][55][56][57][58] As a consequence, it appears that the interaction energy E zg could be used in a predictive fashion to identify adsorbents with a high affinity towards a given pollutant. However, it needs to be emphasised that the zeolite-guest interaction energy is an artificial quantity that has no directly measurable experimental analogue, and that any simulation approach aiming at a physically accurate description of the actual adsorption process would necessarily have to be much more complex.…”