MWW-Type Titanosilicate Synthesized by Simply Treating ERB-P Zeolite with Acidic H2TiF6 and Its Catalytic Performance in a Liquid Epoxidation of 1-Hexene with H2O2

Guo, Shujun; Zhang, Yanjie; Ye, Yuansong; Song, Jinzhe; Li, Mengru

doi:10.1021/acsomega.0c00184

Cited by 9 publications

(3 citation statements)

References 36 publications

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“…For example, new large channel systems can be created in 2‐dimensional lamellar zeolites to form “interlayer expanded zeolitic structures”. The most represented example is Ti‐MWW: this material exhibits supercages of 7×18 Å accessible via 7 Å side cup openings, [135,154] and can be delaminated or structurally rearranged to form a large variety of 3D structures [136] . For example Ti‐MCM‐36 is another hierarchical micro‐/meso‐porous zeolite made up of micropores in the crystalline layers and mesopores (2.5 nm) in the interlayer spaces [137] .…”

Section: Strategies To Improve Ti‐based Heterogeneous Epoxidation Catalystsmentioning

confidence: 99%

Titanosilicate Epoxidation Catalysts: A Review of Challenges and Opportunities

2021

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Epoxidation reactions are tremendously important for modern chemistry, as they lead to series of highly useful bulk and fine chemicals, monomers, and intermediates for organic synthesis. Progress in epoxidation processes goes hand in hand with the advancement made in catalysis science. In this context, heterogeneous catalysts, and particularly Ti‐based formulations, are playing a central role and have seen tremendous developments over the past two decades, leveraging on advanced materials science. The aim of this review is to illustrate the various strategies of titanosilicate catalysts preparation that can lead to more versatile, more performant, and greener epoxidation processes. We successively cover (i) supported catalysts, obtained by the grafting of Ti species onto preformed silica supports, (ii) microporous crystalline titanosilicates (zeolites), and (iii) amorphous titanosilicates obtained by sol‐gel chemistry. For each category, with an emphasis on catalyst preparation, the challenges that have to be tackled to boost catalyst performance are highlighted. From that point, we present a critical review of the different approaches that have been proposed in the primary literature to tailor the properties that govern catalysts performance (activity, selectivity, stability, ease of handling). This is done by better controlling the nature of the active surface species, adapting particles size and shape, optimizing texture, modifying surface chemistry, etc. These lines of attack encompass molecular approaches for the grafting of well‐defined species, top‐down and bottom‐up synthesis of hierarchically porous zeolites, advanced sol‐gel routes potentially performed in non‐conventional media or coupled with original processing, preparation of self‐standing monoliths, etc. Future research directions are discussed with emphasis on the application scope of new catalytic materials and possible approaches to increase catalyst performance.

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Section: Strategies To Improve Ti‐based Heterogeneous Epoxidation Catalystsmentioning

confidence: 99%

Titanosilicate Epoxidation Catalysts: A Review of Challenges and Opportunities

2021

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“…However, with the increase of TiO 2 content, the H 2 O 2 average utilization efficiency gradually decreases from 98.29 to 96.66% due to the decomposition of H 2 O 2 by anatase TiO 2 , (Figure c). Moreover, it should be noted that the 0.45 wt % Ti-beta-post with the highest percentage of tetra-coordinated Ti species shows outstanding epoxidation performance of 1-hexene (TON: 401, selectivity: 98.63%, utilization efficiency of H 2 O 2 : 98.29%) compared with the results in literatures ,,− (Figure d).…”

Section: Resultsmentioning

confidence: 63%

Regulating the Coordination Mode of Ti Atoms in the Beta Zeolite Framework to Enhance the 1-Hexene Epoxidation

Deng,

Xu,

Liu

et al. 2024

Ind. Eng. Chem. Res.

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Regulating the Ti active sites in titanosilicates with different coordination modes is of prime scientific and industrial significance to the rational design of efficient catalysts for olefin epoxidation. In this study, the Ti species in Tibeta zeolite catalysts (open/closed tetra-coordinated Ti sites, hexa-coordinated Ti species, and TiO 2 ) were keenly controlled via the dealumination-metallization approach. By multiple characterizations, kinetics study, and multivariate model analysis, it is found that the open tetra-coordinated framework Ti(OH)(OSi) 3 species contribute more to the catalytic performance for 1-hexene epoxidation with H 2 O 2 . Moreover, the Ti-beta with rich open tetra-coordinated Ti(OH)(OSi) 3 species showed significantly improved reaction performance (TON: 401, conversion: 64%, selectivity: 98%, H 2 O 2 efficiency: 97%) with lower apparent activation energy. This study not only opens up new prospects for the design of efficient titanosilicates by modifying Ti microenvironments but also proposes the strategy to improve the content of open tetra-coordinated Ti sites.

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“…Moreover, Re-Ti-MWW-PI [18,19] was hydrothermally synthesized via post-synthesis treated the Ti-MWW with organic amines exhibit much higher activity than conventional Ti-MWW-HTS in the epoxidation of alkenes. Nevertheless, in spite of the excellent catalytic performance in oxidation of bulky molecules, there is still a significant challenge for the directly synthesis of Ti-MWW zeolite due to its complex 3D framework structure [20]. Furthermore, the preparation of Ti-MWW is typically under hydrothermal conditions, where a large amount of solvents is necessary, which accompanied with a lot of shortcomings such as high energy consumption and long crystallization period caused by the low utilization efficiency of the nutrients of silicates [8,[21][22][23].…”

Section: Introductionmentioning

confidence: 99%