Computational Evaluation of the Diffusion Mechanisms for C8 Aromatics in Porous Organic Cages

Jackson, Edward; Miklitz, Marcin; Song, Qilei; Tribello, Gareth A.; Jelfs, Kim E.

doi:10.1021/acs.jpcc.9b05953

Cited by 13 publications

(8 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The kinetic diameter of the PX molecule is 5.8 Å. 43 If h is chosen to be 5.48 Å, the HS-entering probability will be zero. Considering the planarity of the benzene ring, the molecular structure is extremely anisotropic, and the average pore diameter underestimates the HS-entering probability of the PX molecule.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Molecular Dynamics Simulations on the Entrance of Methane and p-Xylene into ZSM-5 Zeolite

Zhao

Huang

2021

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The significant influence of interfacial resistance on the overall mass transfer performance, especially for catalysis with zeolites, has attracted a lot of attention, but the understanding on entering-pore processes is still very limited in comparison with that on intracrystalline diffusion processes. Evaluating entering probabilities still depends frequently on the expressions derived from hard sphere (HS) simulations where substantial approximations exist. In this work, molecular dynamics simulations have been performed to elucidate the interfacial barriers involved in methane and p-xylene (PX) molecules entering the ZSM-5 zeolite. The entering probabilities have been derived accordingly, along with the occupancy distributions and the residence time distributions of the incident molecules. The results have been compared with those of HS simulations in the literature as well. It is observed that the occupancy distribution of these two species exhibits peaks along the entering paths, reflecting the apparent resistance due to adsorption, which cannot be revealed through HS simulations. Bimodal distributions have also been observed, which can be attributed to the coexistence of the separate adsorption and entering-pore processes. With the increase in temperature, such peaks tend to level off, approaching the results of HS simulations. The entering probabilities of these two species approach the results from HS simulations as well at high temperatures. Because the entering probabilities of the two species show different decreasing slopes with temperature, at low temperatures, the entering probability of PX molecules can be higher than that of methane molecules. However, the entering rate of the PX molecules is always quite lower than that of the methane molecules because of its much longer residence time. Such phenomena have been explained on the basis of entropic and energetic effects. Based on a pseudo-reaction model, the results of the entering probabilities have been well fitted, and an expression has been proposed accordingly, which is expected to be applied to large-scale models. Because such an expression is developed on a more sophisticated ground than HS simulations, its applications might lead to more satisfactory results.

show abstract

Section: Resultsmentioning

confidence: 99%

“…The kinetic diameter of the PX molecule is 5.8 Å . If h is chosen to be 5.48 Å, the HS-entering probability will be zero.…”

Section: Resultsmentioning

confidence: 99%

Molecular Dynamics Simulations on the Entrance of Methane and p-Xylene into ZSM-5 Zeolite

Zhao

Huang

2021

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…(e) How about the position of the disordered solvent molecules located within the prefabricated pores? In response to these questions, computational methods have been extended to the field of POCs with a few recent examples − that have been successful.…”

Section: Strategic Design Of Porous Organic Cagesmentioning

confidence: 99%

“…In a recent study, molecular dynamics simulations indicated that the imine cage 12 undergoes a structural collapse to a nonporous form, a result which matches (Figure d) well with experimental observations. In addition, by calculating the host–guest interaction energies, molecular dynamics simulations also predict the diffusion mechanisms and selectivity for C8 aromatics in POCs.…”

Section: Strategic Design Of Porous Organic Cagesmentioning

confidence: 99%

Porous Organic Cages

2023

View full text Add to dashboard Cite

Porous organic cages (POCs) are a relatively new class of low-density crystalline materials that have emerged as a versatile platform for investigating molecular recognition, gas storage and separation, and proton conduction, with potential applications in the fields of porous liquids, highly permeable membranes, heterogeneous catalysis, and microreactors. In common with highly extended porous structures, such as metal−organic frameworks (MOFs), covalent organic frameworks (COFs), and porous organic polymers (POPs), POCs possess all of the advantages of highly specific surface areas, porosities, open pore channels, and tunable structures. In addition, they have discrete molecular structures and exhibit good to excellent solubilities in common solvents, enabling their solution dispersibility and processability�properties that are not readily available in the case of the well-established, insoluble, extended porous frameworks. Here, we present a critical review summarizing in detail recent progress and breakthroughs�especially during the past five years�of all the POCs while taking a close look at their strategic design, precise synthesis, including both irreversible bond-forming chemistry and dynamic covalent chemistry, advanced characterization, and diverse applications. We highlight representative POC examples in an attempt to gain some understanding of their structure−function relationships. We also discuss future challenges and opportunities in the design, synthesis, characterization, and application of POCs. We anticipate that this review will be useful to researchers working in this field when it comes to designing and developing new POCs with desired functions.

show abstract

“…[47] With a computational model of the molecular or solid-state structure, it is then possible to perform a variety of calculations to determine the properties of the material, such as poretopology, surface area, guest uptake and selectivity. [48] In the solid-state, these are standard simulations that have been widely applied in the field of porous framework simulations. [49] Given that the prediction of solid-state structure is laborious, it is valuable to be able to estimate some properties of the individual molecule from computationally cheaper molecular simulations.…”

Section: Kim Jelfs Is a Senior Lecturer And Royal Societymentioning

confidence: 99%

High‐Throughput Approaches for the Discovery of Supramolecular Organic Cages

Greenaway

Jelfs

2020

ChemPlusChem

Self Cite

View full text Add to dashboard Cite

The assembly of complex molecules, such as organic cages, can be achieved through supramolecular and dynamic covalent strategies. Their use in a range of applications has been demonstrated, including gas uptake, molecular separations, and in catalysis. However, the targeted design and synthesis of new species for particular applications is challenging, particularly as the systems become more complex. High‐throughput computation‐only and experiment‐only approaches have been developed to streamline the discovery process, although are still not widely implemented. Additionally, combined hybrid workflows can dramatically accelerate the discovery process and lead to the serendipitous discovery and rationalisation of new supramolecular assemblies that would not have been designed based on intuition alone. This Minireview focuses on the advances in high‐throughput approaches that have been developed and applied in the discovery of supramolecular organic cages.

show abstract

Computational Evaluation of the Diffusion Mechanisms for C8 Aromatics in Porous Organic Cages

Cited by 13 publications

References 60 publications

Molecular Dynamics Simulations on the Entrance of Methane and p-Xylene into ZSM-5 Zeolite

Molecular Dynamics Simulations on the Entrance of Methane and p-Xylene into ZSM-5 Zeolite

Porous Organic Cages

High‐Throughput Approaches for the Discovery of Supramolecular Organic Cages

Contact Info

Product

Resources

About