Structure-performance relationship of Mg(OEt)2-based Ziegler-Natta catalysts

Wada, Toru; Funako, Toshiki; Chammingkwan, Patchanee; Thakur, Ashutosh; Matta, Akanksha; Terano, Minoru; Taniike, Toshiaki

doi:10.1016/j.jcat.2020.06.030

Cited by 30 publications

(24 citation statements)

References 59 publications

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“…15 Three TiCl 4 molecules with respect to 50MgCl 2 units correspond to 2.69 wt %, similar to a typical Ti content of industrial Ziegler−Natta catalysts. 23 The structure determination program assumes a convex MgCl 2 monolayer with its lateral surfaces capped by TiCl 4 . A MgCl 2 skeleton consists of N Mg 2+ cations and 2N Cl − anions, respectively, placed at atomic positions in the ionic crystal, where the Cl − anions are placed in the descending order of the coordination number.…”

Section: Computational Models and Detailsmentioning

confidence: 99%

Spectroscopic Fingerprints of MgCl₂/TiCl₄ Nanoclusters Determined by Machine Learning and DFT

et al. 2021

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Understanding the structure and properties of MgCl2/TiCl4 nanoclusters is a key to uncovering the origin of Ziegler–Natta catalysis. In particular, vibrational spectroscopy can sensitively probe the morphology and active species of MgCl2/TiCl4. Here, we determined vibrational spectroscopic fingerprints of 50MgCl2 and 50MgCl2/3TiCl4 which were obtained by nonempirical structure determination based on an evolutionary algorithm and DFT. The adsorption of CO, TiCl4, and Ti2Cl8 dimers was also modeled on each of the coordinatively unsaturated Mg2+ sites available for binding including so-called defect sites, which are likely present at the surface of activated MgCl2 nanocrystals and plausible sites for strong TiCl4 species adsorption. The outcomes of thermodynamical and vibrational analysis were compared to results on ideal surfaces of MgCl2. Vibrational analysis (IR and Raman) on plausible models of TiCl4/ MgCl2 nanoclusters revealed that IR response is useful for distinguishing between the different ways of binding of TiCl4 on different sites of adsorption, whereas Raman response provides a clear fingerprint of supported TiCl4 species.

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Section: Computational Models and Detailsmentioning

confidence: 99%

Spectroscopic Fingerprints of MgCl₂/TiCl₄ Nanoclusters Determined by Machine Learning and DFT

et al. 2021

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“…The size of nanoclusters is about 3 nm in diameter, comparable with the experimental size of the catalyst primary particles (ca. 2.4-4.0 nm) [40]; at the meantime the ratio between TiCl 4 molecules and MgCl 2 units equal to 50/3 corresponds to 2.69 wt%, similar to Ti content in a typical Ziegler-Natta catalyst [57,58,64,65]. The DFT [66,67] calculations reported in this paper were mainly based on the B3LYP global hybrid functional [68,69], as implemented in the CRYSTAL program [70,71].…”

Section: Computational Models and Dft Calculations Detailsmentioning

confidence: 98%

Effect of Internal Donors on Raman and IR Spectroscopic Fingerprints of MgCl2/TiCl4 Nanoclusters Determined by Machine Learning and DFT

et al. 2022

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To go deep into the origin of MgCl2 supported Ziegler-Natta catalysis we need to fully understand the structure and properties of precatalytic nanoclusters MgCl2/TiCl4 in presence of Lewis bases as internal donors (ID). In this work MgCl2/TiCl4 nanoplatelets derived by machine learning and DFT calculations have been used to model the interaction with ethyl-benzoate EB as ID, with available exposed sites of binary TixCly/MgCl2 systems. The influence of vicinal Ti2Cl8 and coadsorbed TiCl4 on energetic, structural and spectroscopic behaviour of EB has been considered. The adsorption of homogeneous-like TiCl4EB and TiCl4(EB)2 at the various surface sites have been also simulated. B3LYP-D2 and M06 functionals combined with TZVP quality basis set have been adopted for calculations. The adducts have been characterized by computing IR and Raman spectra that have been found to provide specific fingerprints useful to identify surface species; IR spectra have been successfully compared to available experimental data.

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“…Initially, PA was polymerized by using Ziegler–Natta catalysts [ 93 , 94 , 95 ] in which acetylene gas was used. Lately, PA has been produced by using radiation polymerization via ultraviolet [ 96 ], gamma [ 33 ], or glow-discharge [ 97 ] radiations.…”

Section: Electrically Conductive Mediamentioning

confidence: 99%

Irreversible and Self-Healing Electrically Conductive Hydrogels Made of Bio-Based Polymers

Nada

Andicsová

Mosnáček

2022

IJMS

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Electrically conductive materials that are fabricated based on natural polymers have seen significant interest in numerous applications, especially when advanced properties such as self-healing are introduced. In this article review, the hydrogels that are based on natural polymers containing electrically conductive medium were covered, while both irreversible and reversible cross-links are presented. Among the conductive media, a special focus was put on conductive polymers, such as polyaniline, polypyrrole, polyacetylene, and polythiophenes, which can be potentially synthesized from renewable resources. Preparation methods of the conductive irreversible hydrogels that are based on these conductive polymers were reported observing their electrical conductivity values by Siemens per centimeter (S/cm). Additionally, the self-healing systems that were already applied or applicable in electrically conductive hydrogels that are based on natural polymers were presented and classified based on non-covalent or covalent cross-links. The real-time healing, mechanical stability, and electrically conductive values were highlighted.

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Structure-performance relationship of Mg(OEt)2-based Ziegler-Natta catalysts

Cited by 30 publications

References 59 publications

Spectroscopic Fingerprints of MgCl₂/TiCl₄ Nanoclusters Determined by Machine Learning and DFT

Spectroscopic Fingerprints of MgCl₂/TiCl₄ Nanoclusters Determined by Machine Learning and DFT

Effect of Internal Donors on Raman and IR Spectroscopic Fingerprints of MgCl2/TiCl4 Nanoclusters Determined by Machine Learning and DFT

Irreversible and Self-Healing Electrically Conductive Hydrogels Made of Bio-Based Polymers

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