scholarly journals Surfactant-assisted synthesis of Mo–V mixed oxide catalysts for upgraded one-step conversion of glycerol to acrylic acid

RSC Advances ◽  
2018 ◽  
Vol 8 (22) ◽  
pp. 11975-11982 ◽  
Author(s):  
Letícia F. Rasteiro ◽  
Luiz H. Vieira ◽  
Celso V. Santilli ◽  
Leandro Martins

Rod-like crystals of Mo–V mixed oxides obtained by surfactant-assisted synthesis are very stable and highly efficient to one-step conversion of glycerol into acrylic acid.

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 593 ◽  
Author(s):  
Pacultová ◽  
Bílková ◽  
Klegova ◽  
Karásková ◽  
Fridrichová ◽  
...  

Fundamental research on direct NO decomposition is still needed for the design of a sufficiently active, stable and selective catalyst. Co-based mixed oxides promoted by alkali metals are promising catalysts for direct NO decomposition, but which parameters play the key role in NO decomposition over mixed oxide catalysts? How do applied preparation conditions affect the obtained catalyst’s properties?


2014 ◽  
Vol 4 (10) ◽  
pp. 3713-3722 ◽  
Author(s):  
Hisahiro Einaga ◽  
Akihiro Kiya ◽  
Satoru Yoshioka ◽  
Yasutake Teraoka

Copper–manganese (Cu–Mn) mixed oxide catalysts were prepared by a coprecipitation technique from metal nitrates in aqueous solution using tetramethylammonium hydroxide (TMAH) as a pH regulator.


2015 ◽  
Vol 5 (12) ◽  
pp. 5062-5076 ◽  
Author(s):  
Itika Kainthla ◽  
Jayesh T. Bhanushali ◽  
Rangappa S. Keri ◽  
Bhari Mallanna Nagaraja

The activity of V, Fe and carbon based catalysts depends on V5+, Fe3+and active carbon sites. The mixed oxide catalysts show superior activity than individual oxides.


2013 ◽  
Vol 2 (2) ◽  
pp. 173-180 ◽  
Author(s):  
Shengxi Yao ◽  
Xicheng Wang ◽  
Yijun Jiang ◽  
Feng Wu ◽  
Xinguo Chen ◽  
...  

2014 ◽  
Vol 37 (3) ◽  
pp. 398-408 ◽  
Author(s):  
Alfons Drochner ◽  
Philip Kampe ◽  
Nadine Menning ◽  
Nina Blickhan ◽  
Tim Jekewitz ◽  
...  

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4341 ◽  
Author(s):  
Fang Liu ◽  
Li Yang ◽  
Jie Cheng ◽  
Xin Wu ◽  
Wenbin Quan ◽  
...  

The selective catalytic reduction of NOx (deNOx) at temperatures less than or at 200 °C was investigated while using C2H4 as the reductant and mixed oxides of Fe and Mn supported on activated carbon; their activity was compared to that of MnOx and FeOx separately supported on activated carbon. The bimetallic oxide compositions maintained high NO conversion of greater than 80–98% for periods that were three times greater than those of the supported monometallic oxides. To examine potential reasons for the significant increases in activity maintenance, and subsequent deactivation, the catalysts were examined by using bulk and surface sensitive analytical techniques before and after catalyst testing. No significant changes in Brunauer-Emmett-Teller (BET) surface areas or porosities were observed between freshly-prepared and tested catalysts whereas segregation of FeOx and MnOx species was readily observed in the mono-oxide catalysts after reaction testing that was not detected in the mixed oxide catalysts. Furthermore, x-ray diffraction and Raman spectroscopy data detected cubic Fe3Mn3O8 in both the freshly-prepared and reaction-tested mixed oxide catalysts that were more crystalline after testing. The presence of this compound, which is known to stabilize multivalent Fe species and to enhance oxygen transfer reactions, may be the reason for the high and relatively stable NO conversion activity, and its increased crystallinity during longer-term testing may also decrease surface availability of the active sites responsible for NO conversion. These results point to a potential of further enhancing catalyst stability and activity for low temperature deNOx that is applicable to advanced SCR processing with lower costs and less deleterious side effects to processing equipment.


Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 854 ◽  
Author(s):  
Wladimir Reschetilowski ◽  
Matthias Hauser ◽  
Felix Alscher ◽  
Mandy Klauck ◽  
Grit Kalies

The demand for 1,3-butadiene, one of the most important raw materials in the rubber industry, is constantly increasing. The Lebedev process is a classical method of producing 1,3-butadiene from ethanol, which is to be optimized with regard to the mixed oxide catalysts used. In this work, the binary MgO/SiO2 solid system was tested with regard to its optimum chemical composition for the catalytic conversion of ethanol to 1,3-butadiene. Furthermore, novel mesoporous mixed oxides were prepared to investigate their textural, structural, and surface chemical properties as well as the catalytic activity. Nitrogen physisorption, scanning electron microscopy (SEM), and temperature-programmed ammonia desorption (NH3-TPD) measurements were carried out and evaluated. It was shown that the optimum yield of 1,3-butadiene is achieved by using MgO/SiO2 mixed oxide catalysts with 85–95 mol% MgO and not, as suggested by Lebedev, with 75 mol% MgO. The NH3-TPD measurements revealed that the maximum acid-site density is achieved with an equimolar up to magnesium-rich composition. During the synthesis of binary MgO/SiO2 solid systems based on mesoporous MgO, a thermally stable and ordered structure was formed in the autoclave, depending on the carbonate used and on the duration of the treatment.


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