Liquid-Phase Catalytic Oxidation of Styrene by a Fiber-Supported Copper(II) Complex with High Catalytic Performance

2014 ◽  
Vol 1033-1034 ◽  
pp. 61-64 ◽  
Author(s):  
Hong Hong Yang ◽  
Ge Wang ◽  
Shan Shan Yan ◽  
Jing Feng ◽  
Zhen Dong Liu ◽  
...  

A new type of polymer-supported catalyst, [PS-(PBIM)2Cu (II)], was synthesized by loading 2-(2’-pyridyl) benzimidazole on chloromethylated propylene-styrene graft copolymer fiber and subsequent treatment with Cu (OAc)2 in methanol. The prepared catalyst was used in the oxidation of styrene with tert-butyl hydroperoxide (TBHP) as the oxidant. The important reaction conditions, such as the reaction temperature, the ratio of oxidant/styrene, and the recycle times were examined. The experimental results show that the catalyst reveals relatively high catalytic performance with 84% conversion for styrene. The suitable conditions are as follows: n (styrene):n (TBHP)=1:3, the reaction temperature of 80 °C and the reaction time of 8 h. In addition, the catalyst used repeatedly for 3 times can still possess high catalytic activity.

2006 ◽  
Vol 980 ◽  
Author(s):  
Toshiyuki Hirano

AbstractWe have successfully developed thin foils of boron-free Ni3Al (below 100 μm in thickness) by cold rolling, and recently found that the foils exhibit high catalytic activity for methanol decomposition. A little has been known about catalytic activity in Ni3Al. Even more interestingly, the high catalytic activity appears on flat foils whose surface area is very low. This paper provides a review of the characteristic features of the catalytic properties investigated in my group. Methanol was effectively decomposed into H2 and CO over the foils above 713 K. The production rates of H2 and CO increased with an increase of time during the initial period of reaction, indicating that the Ni3Al foils were spontaneously activated under the reaction conditions. Surface analyses revealed that fine Ni particles dispersed on carbon nanofibers formed on the foils during the reaction. The high catalytic performance of the foils can be attributed to the spontaneous formation of this nanostructure during the reaction.


2019 ◽  
Vol 6 (8) ◽  
pp. 190166
Author(s):  
Ran Liu ◽  
Ke Zhang ◽  
Chen Liu ◽  
Yanhui Hu ◽  
Lilong Zhou ◽  
...  

Four kinds of functional ionic liquids (ILs) ([C 3 SO 3 Hnmp]HSO 4 ), 1-(3-sulfopropyl)-1-methylpyrrolidone phosphate ([C 3 SO 3 Hnmp]H 2 PO 4 ), 1-(3-sulfopropyl)-1-methylpyrrolidone p-toluene sulfonate ([C 3 SO 3 Hnmp]CH 3 SO 3 H) and 1-(3-sulfopropyl)-1-methylpyrrolidone methyl sulfonate ([C 3 SO 3 Hnmp]C 6 H 6 SO 3 H)) were prepared and the catalytic activity of these ILs during esterification of carboxylic acids (formic acid, acetic acid, propionic acid, butyric acid) with alcohols was investigated. The results indicated that the IL ([C 3 SO 3 Hnmp]HSO 4 ) exhibited an optimal catalytic performance. And then the IL ([C 3 SO 3 Hnmp]HSO 4 ) was immobilized to the silica gel. The immobilized IL performed more excellent catalytic activity than the unsupported [C 3 SO 3 Hnmp]HSO 4 . The effects of reaction temperature, reaction time, molar ratio of acid to alcohol and catalyst dosage were investigated. The response surface methodology based on the Box–Behnken design (BBD) was used to explore the best reaction condition of different experimental variables. Accordingly, a high n -butyl butyrate yield of 97.10% under the deduced optimal reaction conditions was obtained, in good agreement with experimental results and that predicted by the BBD model. The immobilized IL [C 3 SO 3 Hnmp]HSO 4 maintained high catalytic activity after five cycles.


RSC Advances ◽  
2016 ◽  
Vol 6 (99) ◽  
pp. 97399-97403 ◽  
Author(s):  
Rui Kuang ◽  
Luyi Zheng ◽  
Ethan Cottrill ◽  
Ning Pan ◽  
Yanhui Chi ◽  
...  

A hierarchical porous MOF nanocrystal, hpCuL (L = 2,4,6-tris(3,5-dicarboxylatephenylamino)-1,3,5-triazine) was prepared via a facile gel-aging process. This nanocomposite exhibits high catalytic activity and stability for the reduction of 4-nitrophenol.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.


2014 ◽  
Vol 924 ◽  
pp. 217-226 ◽  
Author(s):  
Xiang Feng Hu ◽  
Wen Yang ◽  
Ning Wang ◽  
Shi Zhong Luo ◽  
Wei Chu

Nickel/carbon nanotubes (Ni/CNTs), Nickel/alumina (Ni/Al2O3), calcium-promoted Ni/CNTs and calcium-promoted Ni/Al2O3 were synthesized by impregnation method. Methanation of carbon dioxide was used as a probe to evaluate their catalytic performance. The features of these Ni-based catalysts were investigated via XRD, H2-TPR, H2-TPD and the N2 adsorptiondesorption isotherms. H2-TPR showed that nickel species on Ni/CNTs was reduced more easily with respect to that on Ni/Al2O3, and addition of Ca can increase the content of easily reducible Ni species for Ni/CNTs. XRD and H2-TPD indicated that addition of Ca promoted dispersion for CNTs-supported catalyst. These finding ultimately enhanced catalytic activity and stability for Ni/CNTs catalyst modified with Ca.


2013 ◽  
Vol 483 ◽  
pp. 38-41
Author(s):  
Shu Heng Liu

Take Waugh-Type (NH4)6[MnMo9O32] •8H2O absorbed on diatomite and prepared supported solid catalyst. The properties of the catalyst were studied through the synthesis of benzyl acetate. The appropriate reaction conditions were obtained by orthogonal test: mole ratio of acetic acid to benzyl alcohol was 2.5:1.0, the catalyst dosage was 1.6g, the water carrying agent toluene dosage was 2.5ml, reaction time was 150min, esterification yield was 87.4%. The catalyst are high catalytic activity and non- polluting, and could be reused.


2019 ◽  
Vol 55 (48) ◽  
pp. 6862-6865 ◽  
Author(s):  
Yong Xu ◽  
Jiang Mo ◽  
Guanqun Xie ◽  
Dawei Ding ◽  
Shujiang Ding ◽  
...  

Co1.11Te2 enwrapped in a carbon layer displayed high catalytic performance for photocatalytic CO2 reduction. The strong electron transfer ability and the low energy barrier are the key factors that promote its high catalytic activity.


2013 ◽  
Vol 821-822 ◽  
pp. 1081-1084 ◽  
Author(s):  
Xian Ye Qin ◽  
Biao Liu ◽  
Bing Han ◽  
Wen Bo Zhao ◽  
Shui Sheng Wu ◽  
...  

The catalytic activity of many Lewis and Bronsted acid for the synthesis of diethyl carbonate (DEC) from ethyl carbamate (EC) and ethanol was evaluated in a bath reactor. Pyrophosphoric acid (H4P7O2) which showed the best activity was selected to further investigate the effect of reaction conditions, such as reaction temperature, catalyst dose and reaction time, on the yield of DEC. Under the optimal conditions, DEC yield can reach 29.1%.


RSC Advances ◽  
2015 ◽  
Vol 5 (84) ◽  
pp. 68655-68661 ◽  
Author(s):  
Yuanyuan Ma ◽  
Hui Wang ◽  
Weizhong Lv ◽  
Shan Ji ◽  
Bruno G. Pollet ◽  
...  

Amorphous PtNiP particle networks with different particle sizes prepared via the reaction temperature control method showed high catalytic activity for hydrazine oxidation compared to the Pt and PtNi catalysts due to its porous, amorphous structure.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5506
Author(s):  
Daniel Carreira Batalha ◽  
Márcio José da Silva

Nowadays, the synthesis of biofuels from renewable raw materials is very popular. Among the various challenges involved in improving these processes, environmentally benign catalysts compatible with an inexpensive feedstock have become more important. Herein, we report the recent advances achieved in the development of Niobium-containing heterogeneous catalysts as well as their use in routes to produce biodiesel. The efficiency of different Niobium catalysts in esterification and transesterification reactions of lipids and oleaginous raw materials was evaluated, considering the effect of main reaction parameters such as temperature, time, catalyst load, and oil:alcohol molar ratio on the biodiesel yield. The catalytic performance of Niobium compounds was discussed considering the characterization data obtained by different techniques, including NH3-TPD, BET, and Pyr-FT-IR analysis. The high catalytic activity is attributed to its inherent properties, such as the active sites distribution over a high specific surface area, strength of acidity, nature, amount of acidic sites, and inherent mesoporosity. On top of this, recycling experiments have proven that most Niobium catalysts are stable and can be repeatedly used with consistent catalytic activity.


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