Fluoride etching opens access for bulky molecules to active sites in microporous Ti-beta zeolite

2020 ◽  
Vol 4 (10) ◽  
pp. 2982-2989
Author(s):  
Guoju Yang ◽  
Ziyi Qiu ◽  
Ji Han ◽  
Xiaoxin Chen ◽  
Jihong Yu
Keyword(s):  
Active Sites ◽  
Beta Zeolite ◽  
Zeolite P ◽  
Chemically Selective

Non-chemically selective fluoride etching opens access for bulky molecules to active sites in microporous Ti-beta zeolite.

Transformation synthesis of aluminosilicate SSZ-39 zeolite from ZSM-5 and beta zeolite

2019 ◽  
Vol 7 (9) ◽  
pp. 4420-4425 ◽  
Author(s):  
Hao Xu ◽  
Wei Chen ◽  
Qinming Wu ◽  
Chi Lei ◽  
Juan Zhang ◽  
...  
Keyword(s):  
Beta Zeolite ◽  
Zeolite P

Aluminosilicate SSZ-39 zeolite has been prepared by transformation from ZSM-5 and beta zeolite in the presence of N,N-diethyl-cis-2,6-dimethylpiperidinium hydroxide.

DFT exploration of active site motifs in methane hydroxylation by Ni-ZSM-5 zeolite

2018 ◽  
Vol 8 (22) ◽  
pp. 5875-5885 ◽  
Author(s):  
Muhammad Haris Mahyuddin ◽  
Kazunari Yoshizawa
Keyword(s):  
Dft Calculations ◽  
Active Site ◽  
Active Sites ◽  
Zeolite P

DFT calculations suggest [Ni2(μ-O)2]2+ and [Ni3(μ-O)3]2+ species as two possible active sites in methane hydroxylation by Ni-ZSM-5 zeolite. Both of them are predicted to activate methane and desorb the formed methanol with low activation and desorption energies.

scholarly journals Readily available Ti-beta as an efficient catalyst for greener and sustainable production of campholenic aldehyde

2019 ◽  
Vol 9 (16) ◽  
pp. 4293-4303 ◽  
Author(s):  
Marta Puche Panadero ◽  
Alexandra Velty
Keyword(s):  
Sustainable Production ◽  
Beta Zeolite ◽  
Synthetic Route ◽  
Efficient Catalyst ◽  
Campholenic Aldehyde ◽  
Zeolite P

Different Ti-beta zeolite samples were prepared following a convenient and optimized post-synthetic route and starting from commercial Al-beta zeolite.

Zeolitic behaviour of paratoluenesulfonic acid-modified clay in Friedel-Crafts synthesis of raspberry ketone

Clay Minerals ◽  
2015 ◽  
Vol 50 (5) ◽  
pp. 573-581 ◽  
Author(s):  
M. Lakshmy ◽  
B.M. Chandrasekhar ◽  
B.S. Jai Prakash ◽  
Y.S. Bhat
Keyword(s):  
Microwave Irradiation ◽  
Active Sites ◽  
Product Distribution ◽  
Beta Zeolite ◽  
Alkylation Reaction ◽  
Clay Sample ◽  
Raspberry Ketone ◽  
Clay Surface ◽  
Modified Montmorillonite ◽  
Montmorillonite Clays

AbstractDuring solventless alkylation of phenol with 4-hydroxy-2-butanone under microwave irradiation, paratoluenesulfonic acid (pTSA)-modified montmorillonite clays gave, regioselectively, 4-(4′-hydroxyphenyl)-2-butanone (raspberry ketone). The duration for this reaction under microwave irradiation is much shorter than that of the conventional method. A comparative study of the alkylation reaction over a montmorillonite clay sample treated with 0.5 M-pTSA (0.5 M-pTSA clay) with that of Al-exchanged montmorillonite (Al3+-Mont) and beta-zeolite (HB) was carried out. The results show that the reaction time to reach equilibrium and the product distribution pattern for the reaction over 0.5 M-pTSA clay were similar to those values for the HB. Micropores formed on the clay surface during the pTSA treatment were found to enhance the rate of formation of C-alkylation. Micropores appear to enable better access to the active sites during the course of reaction.

A strategy of ketalization for the catalytic selective dehydration of biomass-based polyols over H-beta zeolite

2018 ◽  
Vol 20 (3) ◽  
pp. 634-640 ◽  
Author(s):  
Penghua Che ◽  
Fang Lu ◽  
Xiaoqin Si ◽  
Hong Ma ◽  
Xin Nie ◽  
...  
Keyword(s):  
Beta Zeolite ◽  
Sugar Alcohols ◽  
Vicinal Diol ◽  
Zeolite P

A strategy is presented to control the etherification site in sugar alcohols via ketalization of the terminal vicinal-diol group with a ketone.

scholarly journals Active sites and mechanism of the direct conversion of methane and carbon dioxide to acetic acid over the zinc-modified H-ZSM-5 zeolite

2019 ◽  
Vol 9 (22) ◽  
pp. 6297-6307 ◽  
Author(s):  
Peng Zhang ◽  
Xuejing Yang ◽  
Xiuli Hou ◽  
Jianli Mi ◽  
Zhizhong Yuan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Acetic Acid ◽  
Catalytic Activity ◽  
Active Sites ◽  
Direct Conversion ◽  
Conversion Of Methane ◽  
Zeolite P

The catalytic activity of the conversion of CH4 and CO2 on zinc modified H-ZSM-5 is strongly dependent on the structure of the active sites.

scholarly journals Interplay of the adsorption of light and heavy paraffins in hydroisomerization over H-beta zeolite

2019 ◽  
Vol 9 (19) ◽  
pp. 5368-5382 ◽  
Author(s):  
Pedro S. F. Mendes ◽  
Céline Chizallet ◽  
Javier Pérez-Pellitero ◽  
Pascal Raybaud ◽  
João M. Silva ◽  
...  
Keyword(s):  
Beta Zeolite ◽  
Zeolite P

Hydroisomerization: controlling selectivity by tuning the Pt/zeolite properties.

One-pot cascade transformation of xylose into γ-valerolactone (GVL) over bifunctional Brønsted–Lewis Zr–Al-beta zeolite

2016 ◽  
Vol 18 (21) ◽  
pp. 5777-5781 ◽  
Author(s):  
Blanca Hernández ◽  
Jose Iglesias ◽  
Gabriel Morales ◽  
Marta Paniagua ◽  
Clara López-Aguado ◽  
...  
Keyword(s):  
Zeolite Catalysts ◽  
Beta Zeolite ◽  
Cascade Process ◽  
Synthetic Methodology ◽  
One Pot ◽  
The One ◽  
Zeolite P

Bifunctional Brønsted–Lewis, Zr- and Al-containing beta zeolite catalysts prepared by a post-synthetic methodology promote the one-pot production of γ-valerolactone (GVL) from xylose in alcohol media through a cascade process.

Enhanced Room-Temperature Catalytic Decomposition of Cumene Hydroperoxide into Phenol and Acetone

2021 ◽  
Vol 13 (7) ◽  
pp. 1246-1252
Author(s):  
Hsiu-Ling Hsu ◽  
Rima D. Alharthy
Keyword(s):  
Particle Size ◽  
Active Sites ◽  
Room Temperature ◽  
Ageing Time ◽  
Cumene Hydroperoxide ◽  
Catalytic Decomposition ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Beta Zeolite ◽  
Nano Crystalline

ABSTRACTPhenol is an important industrial chemical that was manufactured by the Hock process. The sulphuric acid used in the Hock process to break cumene hydroperoxide into phenol and acetone suffers from environmental problems along with low selectivity towards the desired products. There are several solid acid catalysts have been tried in cumene hydroperoxide decomposition into an ecofriendly process. In the present work, an efficient environmentally friendly and economically benefitted zeolite-based catalyst was synthesized and tested for breaking cumene hydroperoxide (CHPO) into phenol and acetone. Beta zeolite and ZSM-5 zeolite were synthesised with nano crystalline geometry by hydrothermal method and tested their efficiency to break CHPO. The morphology and structure of nanocrystalline zeolite materials was investigated by Dynamic Light Scattering (DLS), X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) methods. From DLS studies it is documented that the zeolite particle size is tuneable as evidenced from particle size growths with the ageing time under hydrothermal treatment process. XRD analysis confirms the zeolite Beta and ZSM-5. The mean crystal size of Beta and ZSM-5 obtained from SEM analysis are 45 nm and 18.3 nm respectively. The optimization of reaction conditions for CHPO decomposition such as catalyst quantity and initial concentration of CHPO has been done using nanocrystalline Beta catalyst. The optimum catalyst amount and concentration of CHPO are 0.03 g and 15 mmol respectively. The results showed that the nanocrystalline Beta zeolite catalyst exhibits exceptional activity with 100% conversion of CHPO and yielded exclusively phenol and acetone at room temperature. No other by-products are detected. Also, the catalyst is stable and exhibits high product selectivity for phenol and acetone. The nature of the enhanced activity at room temperature for the decomposition of CHPO is suggested that higher accessibility of the active sites that are proposed to be associated with the zeolite with nano configuration with higher surface area and short distances for diffusion inside the channels in the nanocrystalline zeolite particles. The possibility of commercialization of beta zeolite is proved by complete conversion of CHPO with selective formation of phenol and acetone.

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