Selective isomerization of epoxides using magnetically recyclable ZSM-5 zeolite catalyst

RSC Advances ◽  
2015 ◽  
Vol 5 (96) ◽  
pp. 78441-78447 ◽  
Author(s):  
Phan Huy Hoang ◽  
Bach Nguyen Xuan

The magnetically recyclable ZSM-5 zeolite (MZZ) with high catalytic activity, high efficiency in separation, recycling and long lifetime for epoxide isomerization reaction was presented.

RSC Advances ◽  
2017 ◽  
Vol 7 (16) ◽  
pp. 9551-9561 ◽  
Author(s):  
An Li ◽  
Chen Huang ◽  
Cai-Wu Luo ◽  
Wen-Jun Yi ◽  
Zi-Sheng Chao

Quinoline was synthesized via the typical Skraup approach with a vapor-phase process. The mesoporous Ni/beta zeolite catalyst exhibited high-efficiency catalytic activity and an enhanced ability of anti-deactivation.


2013 ◽  
Vol 91 (4) ◽  
pp. 292-299 ◽  
Author(s):  
Bayardo E. Velasco ◽  
Gustavo López-Téllez ◽  
Nelly González-Rivas ◽  
Iván García-Orozco ◽  
Erick Cuevas-Yañez

Diverse dithioic acid copper complexes exhibit a high catalytic activity in the copper-catalyzed alkyne–azide cycloaddition using several solvents under different temperatures, showing a high efficiency with only 0.005 mmol catalyst/mmol alkyne or less. A dithioic acid copper complex derived from acetophenone was selected and used as the catalyst in the preparation of a library of 1,4-disubstituted-1,2,3-triazoles. This process occurred in high yields and good functional group tolerance.


2021 ◽  
Author(s):  
Jianguo liu ◽  
Jiangmin Sun ◽  
Longlong Ma

The development of high efficiency, excellent selectivity, and super activity metal catalyst for chemical selective hydrogenation of alkynes to olefin is of great significance in the field of the chemical industry. At the same time, the development of a large number of available base metal catalysts for organic conversion remains an important objective of chemical research. Herein, we report a facile preparation of a simple, high catalytic activity, environmentally friendly, and inexpensive biomass carbon material supported nano-nickel catalyst from lignin residue. The entire preparation process of the catalyst is simple, reliable, economical, and environmentally friendly, which provides a potential utilization prospect for large-scale industrial applications of biomass-based carbon material catalysts. Biomass-based lignin residues can not only reduce the high oxidation state of nickel ions into nickel nanoparticles by the in-situ reducing gas generated during the calcination process, but the mesoporous structure of lignin residue also promotes the adsorption of nickel metal, which greatly improved the catalytic activity of biomass-based Ni-based catalysts. The simple synthetic green, cost-effective and sustainable biomass-based Ni-based catalyst shows good performance in the selective hydrogenation of phenylacetylene, reaching 97.2% conversion and 84.3% styrene selectivity, respectively.


2019 ◽  
Vol 55 (29) ◽  
pp. 4218-4221 ◽  
Author(s):  
Lingxi Zhou ◽  
Meichen Guo ◽  
Yao Li ◽  
Qin Gu ◽  
Wenqian Zhang ◽  
...  

A series of wire-in-plate nanostructured electrocatalysts for OER with high catalytic activity were fabricated.


Author(s):  
Libo Deng ◽  
Xiujuan Li ◽  
Yuanyuan Chen ◽  
Weijie Liao ◽  
Lei Qiu ◽  
...  

Single atom catalysts (SACs) stabilized by nitrogen in a carbon support and having maximized atom utilization efficiency and an unsaturated environment exhibit high catalytic activity and selectivity. Incorporating nitrogen into...


2013 ◽  
Vol 453 (3) ◽  
pp. 447-454 ◽  
Author(s):  
Liu Xue ◽  
Shurong Hou ◽  
Min Tong ◽  
Lei Fang ◽  
Xiabin Chen ◽  
...  

Cocaine is a widely abused drug without an FDA (Food and Drug Administration)-approved medication. It has been recognized that an ideal anti-cocaine medication would accelerate cocaine metabolism producing biologically inactive metabolites via a route similar to the primary cocaine-metabolizing pathway, i.e. human BChE (butyrylcholinesterase)-catalysed hydrolysis. However, the native human BChE has a low catalytic activity against cocaine. We recently designed and discovered a BChE mutant (A199S/F227A/S287G/A328W/Y332G) with a high catalytic activity (kcat=5700 min−1, Km=3.1 μM) specifically for cocaine, and the mutant was proven effective in protecting mice from acute cocaine toxicity of a lethal dose of cocaine (180 mg/kg of body weight, LD100). Further characterization in animal models requires establishment of a high-efficiency stable cell line for the BChE mutant production at a relatively larger scale. It has been extremely challenging to develop a high-efficiency stable cell line expressing BChE or its mutant. In the present study, we successfully developed a stable cell line efficiently expressing the BChE mutant by using a lentivirus-based repeated-transduction method. The scaled-up protein production enabled us to determine for the first time the in vivo catalytic activity and the biological half-life of this high-activity mutant of human BChE in accelerating cocaine clearance. In particular, it has been demonstrated that the BChE mutant (administered to mice 1 min prior to cocaine) can quickly metabolize cocaine and completely eliminate cocaine-induced hyperactivity in rodents, implying that the BChE mutant may be developed as a promising therapeutic agent for cocaine abuse treatment.


Author(s):  
Irada Ahmadova Irada Ahmadova

Catalysts play an extremely important role in wildlife and industry. Today it is difficult to describe chemistry and petrochemistry without catalytic processes. Catalytic processes account for 80-85% of oil refining. Therefore, the problem of choosing a catalyst is of interest both from the point of view of quality and quantity. In this paper, the activity of a high silicon zeolite catalyst used in the conversion of isobutene was studied at various temperatures, and it was determined that a sample of the zeolite catalyst during the process initially had no catalytic activity during the conversion of isobutene. The release of liquid products is observed only after the formation of 5-8% of compaction products (PM) on the surface within 25-30 minutes from the beginning. Consequently, modifiers have a positive effect on catalytic activity. In this case, the number and strength of the acid sites of the catalyst changes. The study of isobutene conversion process showed that the formation of liquid products is observed at 150°C. It was shown that in this case in the temperature range 150°C-300°C liquid products of isobutene reaction consist of primarily from aliphatic and at 350°C- 450°C from aromatic hydrocarbons. The process of conversion of hexane-1 on the high-silica zeolite catalyst is studied and it was shown that the decomposition of hexene-1 into ethene and propene is occure at the beginning, at 250°C and then the process takes place in a mixture of the two olefins. It was shown by the using of XRD, TG/DTA methods, that the formed products of seals in the conversion of isobutene and 1-hexene over the high silica zeolite catalyst,is composed of two phases that differ from each other in thermal stability. The obtained liquid products during the conversion of isobutene at 150°C-300°C can be used as high-octane gasoline fractions as motor fuel component. The adsorbed NH3 probe molecules method showed that during the conversion of propene, isobutene and hexene-1, the amount of acid sites of spent catalysts is reduced by 43-50%. In this state, the catalyst exhibits high catalytic activity. Keywords: catalyst, activity, isobutene, zeolite.


2015 ◽  
Vol 51 (43) ◽  
pp. 9010-9013 ◽  
Author(s):  
Le Xu ◽  
Da-Ding Huang ◽  
Chen-Geng Li ◽  
Xinyi Ji ◽  
Shaoqing Jin ◽  
...  

An organic–inorganic titanosilicate with an amine ligand shows high catalytic activity, selectivity and recyclability in alkene epoxidation.


Sign in / Sign up

Export Citation Format

Share Document