Rational construction of multiple hollow silicalite-1 zeolite with enhanced quasi acidity for robust vapor-phase Beckmann rearrangement

Zhang, Peng; Yi, Xiaoyan; Xia, Changjiu; Peng, Xinxin; Zhang, Shuai; Li, Chengxiang; Zheng, Anmin; Zhang, Xiaoxin; Luo, Yang; Cui, Lifeng; Fang, Yu; Shu, Xingtian

doi:10.1007/s12274-022-5305-3

Cited by 6 publications

(8 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Zhang et al [142] reported hierarchical silicalite-1 zeolites with three different porous structures have been successfully synthesized and applied in the vapour phase Beckmann rearrangement. Owing to the advantage of short diffusion paths, all hierarchical silicalite -1 zeolites exhibit faster diffusivity than bulky microporous S-1 and improve the caprolactum productivity and selectivity at initial reaction stage.…”

Section: Beckmann Rearrangement In Vapour Phasementioning

confidence: 99%

See 1 more Smart Citation

Comprehensive updates on Beckmann Rearrangement

Kaushik,

Jain,

Malik

et al. 2024

ChemistrySelect

View full text Add to dashboard Cite

Beckmann rearrangement has been quite successful in the preparation of many medicinally potent scaffolds. In synthetic organic chemistry, the Beckmann rearrangement is quite popular, caprolactam is synthesized from cyclohexanone oxime on a large scale for Nylon‐6 production. The function of numerous catalysts and media in the Beckmann rearrangement has been discussed in depth in this review. In the last 20 years, Beckmann rearrangement catalysis has evolved from a potentially hazardous to a more environmentally friendly catalyst, as a result of greater usage. Catalytic performance and synthetic performance of various catalytic systems have been re‐evaluated in the present review article.

show abstract

Section: Beckmann Rearrangement In Vapour Phasementioning

confidence: 99%

“…Zhang et al [142] . reported hierarchical silicalite‐1 zeolites with three different porous structures have been successfully synthesized and applied in the vapour phase Beckmann rearrangement.…”

Section: Miscellaneousmentioning

confidence: 99%

Comprehensive updates on Beckmann Rearrangement

Kaushik,

Jain,

Malik

et al. 2024

ChemistrySelect

View full text Add to dashboard Cite

show abstract

“…Then, the effects of various silanols, especially the terminal silanols and silanol nests, were investigated, − which point out that silanol nests are more effective to catalyze the vapor-phase BR due to the lower reaction barrier than that of terminal silanols. ,, However, the detailed impacts of terminal silanols are still ambiguous. In addition, introducing mesopores or even macropores into zeolite particles has been proven to be an effective way to promote mass diffusivity, − ascribed to the promoted cooperation between reactivity and mass transfer within the confined space.…”

Section: Introductionmentioning

confidence: 99%

Modulating the Microenvironment of Silanols in Pure-Silicon Zeolites for Boosting Vapor-phase Beckmann Rearrangement of Cyclohexanone Oxime

Zhang,

Wang,

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Vapor-phase Beckmann rearrangement of cyclohexanone oxime (CHO) to ε-caprolactam (CPL) is still difficult to commercialize at the industrial scale due to its relatively low catalytic activity and poor lifetime. Herein, we synthesized a series of pure-silicon zeolites (including MFI, MEL, and −SVR) with three-dimensional 10-member-ring topolgies, diverse silanol status, and hierarchical porosity to investigate the synergistic effects of inner diffusivity and reactivity. S-1 zeolite of MFI-type topology with plentiful silanol nests exhibits a more preferable catalytic performance in terms of CHO conversion (99.7%) and CPL selectivity (89.7%), much higher than those of MEL-and −SVRtype zeolites mainly due to their diverse silanol distribution. With the construction of hierarchical porosity, S-1-P shows improved CPL selectivity of 94.1% owing to the enhanced diffusivity to shorten the retention time of the reactant and product molecules. The reaction mechanism and network have been further revealed by density functional theory (DFT) calculations and experimental designs, which indicate that silanol nests are major active sites due to their suitable interaction with CHO rather than terminal silanols. Particularly, the microenvironments of silanols can be modulated by alcohol solvents, ascribed to their different charge transfer and steric hindrance. Consequently, S-1-P shows superior CPL selectivity of 97.3% in ethonal solvents, which have higher adsorb energy of −0.627 eV with silanol nests than other alcohols. The present study not only provides a fundamental guide for the design of zeolite catalysts but also provides a reference for modulating the microenvironment of active sites according to the catalytic mechanism.

show abstract

Section: Introductionmentioning

confidence: 99%

“…The sheet-like macro/microporous Silicalite-1 zeolite prepared in this study was evaluated for its performance as a catalyst for vapor-phase Beckmann rearrangement of cyclohexa-none oxime (CHO) to ε-caprolactam (CP), the monomer for Nylon-6. 37 The reaction formula for CHO to CP is, Currently, more than 90% ε-caprolactam is produced via the conventional cyclohexanone route catalyzed by fuming sulfuric acid. 38 Siliceous MFI zeolites (i.e., Silicalite-1) containing silanol nests, or hydrogen-bonded silanol groups, which are mild acids, have been investigated as promising heterogenous catalysts for the vapor-phase Beckmann rearrangement of cyclohexanone oxime; however, the micropores in Silicalite-1 readily accumulate coke.…”

Section: Introductionmentioning

confidence: 99%