Effect of dispersed ZnO in Cu–Zn composite oxides on catalytic activity of anisole acetylation

2020 ◽  
Vol 44 (25) ◽  
pp. 10492-10499
Author(s):  
Yanqiu Chen ◽  
Yue Yang ◽  
Zhou Zhou ◽  
Wei Luo ◽  
Junhua Liu ◽  
...  

Cu–Zn composite oxide catalysts were prepared by a co-precipitation method and used in the anisole acetylation reaction.

2011 ◽  
Vol 28 (4) ◽  
pp. 1139-1143 ◽  
Author(s):  
Moon Hyeon Kim ◽  
Kyung Ho Cho ◽  
Chae-Ho Shin ◽  
Seong-Eun Kang ◽  
Sung-Won Ham

2013 ◽  
Vol 320 ◽  
pp. 665-669
Author(s):  
Chao Zhang ◽  
Yong Ji Song ◽  
Feng Hua Shi ◽  
Cui Qing Li ◽  
Hong Wang

In this paper, hexaaluminate oxides LaMAl12O19-σwere prepared by using M=Cu ,Ce and Zn as active components to substitute Al in the hexaaluminate lattice by co-precipitation method. The structure and properties of LaMAl11O19-σcatalyst was characterized with XRD and BET. The results showed LaCuAl11O19-σexhibited significant high catalytic activity for the decomposition reaction of N2O. Under the simulated in situ condition, LaCuAl11O19-σalso indicated significant catalytic activity and stability, with N2O conversion of 90% at 635°C.


2012 ◽  
Vol 178-181 ◽  
pp. 562-565
Author(s):  
Rui Cui Liu ◽  
Fu Yi Jiang ◽  
Zi Quan Liu

The experiment used iron chloride, iron dichloride and other agents as the main resources to prepare the nano Fe3O4 powder by co-precipitation method. Magnets were used to test the magnetism of the prepared nano Fe3O4 powder samples. And the photo-catalytic degradation of rhodamine B solution was used as the model reaction to test the photo-catalytic activity of the prepared nano Fe3O4 powder. The results showed that the prepared nano Fe3O4 powder samples had good magnetism but low photo-catalytic activity.


2021 ◽  
Author(s):  
Yani Hua ◽  
Chuan Wang ◽  
Sha Wang ◽  
Juan Xiao

Abstract Fe3O4 magnetic nanoparticles (MNPs) have been widely used as a recyclable catalyst in Fenton reaction for organic degradation. However, the pristine MNPs suffer from the drawbacks of iron leaching in acidic conditions as well as the decreasing catalytic activity of organic degradation at a pH higher than 3.0. To solve the problems, Fe3O4 MNPs were modified by poly(catechol) (Fe3O4/PCC MNPs) using a facile chemical co-precipitation method. The poly(catechol) modification improved both the dispersity and the surface negative charges of Fe3O4/PCC MNPs, which are beneficial to the catalytic activity of MNPs for organics degradation. Moreover, the poly(catechol) modification enhanced the efficiency of Fe(II) regeneration during Fenton reaction due to the acceleration of Fe(III) reduction by the phenolic/quinonoid redox pair. As a result, the Fenton reaction with Fe3O4/PCC MNPs could efficiently degrade organic molecules, exampled by methylene blue (MB), in an expanded pH range between 3.0 and 10.0. In addition, Fe3O4/PCC MNPs could be reused up to 8 cycles for the MB degradation with negligible iron leaching of lower than 1.5 mg L-1. This study demonstrated Fe3O4/PCC MNPs are a promising heterogeneous Fenton catalysts for organic degradation.


Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 542
Author(s):  
Taeho Lim ◽  
Min Su Han

Herein, an easily accessible and efficient green method for the reduction of nitroarene compounds was developed using metal oxide catalysts. Heterogeneous metal oxides with or without Pd were prepared by a simple and scalable co-precipitation method and used for the reduction of nitroarenes. A fluorescence-based high-throughput screening (HTS) method was also developed for the rapid analysis of the reaction conditions. The catalytic activity of the metal oxides and reaction conditions were rapidly screened by the fluorescence-based HTS method, and Pd/CuO showed the highest catalytic activity under mild reaction conditions. After identifying the optimal reaction conditions, various nitroarenes were reduced to the corresponding aniline derivatives by Pd/CuO (0.005 mol% of Pd) under these conditions. Furthermore, the Pd/CuO catalyst was used for the one-pot Suzuki–Miyaura cross-coupling/reduction reaction. A gram-scale reaction (20 mmol) was successfully performed using the present method, and Pd/CuO showed high reusability without a loss of catalytic activity for five cycles.


RSC Advances ◽  
2016 ◽  
Vol 6 (72) ◽  
pp. 68081-68091 ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob ◽  
Mohd Sobri Takriff

Unsupported mesoporous nickel ferrites were successfully synthesized via a facile co-precipitation method and used for the thermocatalytic decomposition of methane into hydrogen and nanocarbon at various reaction temperatures.


Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1435
Author(s):  
Alexander Zubkov ◽  
Tatiana Bugrova ◽  
Mikhail Salaev ◽  
Grigory Mamontov

Two series of chromium–zirconium mixed oxide catalysts with different Cr/Zr molar ratio are prepared by co-precipitation method. Porous structure of the catalysts is studied by low-temperature N2 adsorption–desorption. Phase composition and chromium states in the catalysts are characterized by X-ray diffraction (XRD), UV-visible spectroscopy, and temperature-programmed reduction with hydrogen (TPR-H2). The mixed catalysts are tested in non-oxidative dehydrogenation of propane at 550 °C. The catalysts synthesized without ageing of precipitate show higher activity in propane dehydrogenation due to the higher content of reducible Cr+5/+6 species due to its stabilization on the ZrO2 surface.


2019 ◽  
Vol 19 (3) ◽  
pp. 675
Author(s):  
Salih Hadi Kadhim ◽  
Tariq Hussein Mgheer ◽  
Hussein Idrees Ismael ◽  
Khudheyer Jawad Kadem ◽  
Ahmed Saadon Abbas ◽  
...  

The ternary NiO-CoO-MgO catalyst in three ratios 20:20:60, 25:25:50, and 30:30:40 for these component oxides respectively, were synthesized by co-precipitation method of their carbonates by addition of a precipitate agent in basic media, and then calcinated these carbonate to obtain of mixed oxides. The prepared catalysts were characterized by using Powder X-Ray Diffraction (PXRD), Fourier Infrared spectroscopy (FT-IR), and Atomic Force Microscopy techniques (AFM) were used for identification of the prepared catalysts. The result showed that the particle size of these catalyst ratios, were in the nano range and the smallest size was 25:25:50. The investigation of catalytic activity of prepared catalysts was done by photo decolorization of Celestine blue B dye from simulated industrial wastewaters in aqueous solution. The decolorization efficiency of dye reached 99.9% after irradiation time for 1 h. Study the effect of different reaction conditions such as the pH of the medium, the weight of semiconductor and temperature of mixture reaction were shown that the maximum degradation was observed in conditions at pH = 4, catalyst dosage = 0.08 g, and temperature = 303 K.


2014 ◽  
Vol 633 ◽  
pp. 121-124 ◽  
Author(s):  
Liang Jing Zhang ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Xiao Yu Ma ◽  
Xiao Gen Luo

Catalysts of Mn/TiO2 and Mn-Ce /TiO2 prepared by co-precipitation method for low temperature selective catalytic reduction (SCR) of NO with NH3 were investigated in this study. The experimental results showed that co-precipitation method after improvement, the NO conversion of Mn-Ce/TiO2 catalyst increased sharply. Meanwhile, the addition of cerium has significant effects on the catalytic activity. Characterizations of catalysts were carried out by XRD, BET and H2-TPR. The characterized results indicated that co-precipitation method after improvement, in temperature windows 150 to 300 °C, showed higher NOx conversion.


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