Kinetics of isobutane selective oxidation over Mo-V-P-As-Cs-Cu-O heteropoly acid catalyst

2001 ◽  
Vol 206 (2) ◽  
pp. 183-195 ◽  
Author(s):  
Götz-Peter Schindler ◽  
Toshiaki Ui ◽  
Koichi Nagai
Author(s):  
Emanuele Moioli ◽  
Leo Schmid ◽  
Peter Wasserscheid ◽  
Hannsjoerg Freund

The kinetics of the acid catalyzed reactions of acetaldehyde ammonia trimer (AAT) and paraldehyde (para) to 2-methyl-5-ethyl pyridine (MEP) in the presence of an acid catalyst were investigated systematically. A...


2003 ◽  
Vol 39 (5) ◽  
pp. 605-614 ◽  
Author(s):  
Ya. S. Matychak ◽  
V. S. Pavlyna ◽  
V. M. Fedirko

2021 ◽  
Author(s):  
Meutia Ermina Toif ◽  
Muslikhin Hidayat ◽  
Rochmadi Rochmadi ◽  
Arief Budiman

Abstract Glucose is the primary derivative of lignocellulosic biomass, which is abundantly available. Glucose has excellent potential to be converted into valuable compounds such as ethanol, sorbitol, gluconic acid, and levulinic acid (LA). Levulinic acid is a very promising green platform chemical. It is composed of two functional groups, ketone and carboxylate groups which can act as highly reactive electrophiles for nucleophilic attack so it has extensive applications, including fuel additives, raw materials for the pharmaceutical industry, and cosmetics. The reaction kinetics of LA synthesis from glucose using hydrochloric acid catalyst (bronsted acid) were studied in a wide range of operating conditions, i.e., temperature of 140-180 oC, catalyst concentration of 0.5-1.5 M, and initial glucose concentration of 0.1-0.5 M. The highest LA yield is 48.34 %wt at 0.1 M initial glucose concentration, 1 M HCl, and temperature of 180 oC. The experimental results show that the bronsted acid catalyst's reaction pathway consists of glucose decomposition to levoglucosan (LG), conversion of LG to 5-hydroxymethylfurfural (HMF), and rehydration of HMF to LA. The experimental data yields a good fitting by assuming a first-order reaction model.


2003 ◽  
Vol 249 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jinchang Zhang ◽  
Biaohua Chen ◽  
Chengyue Li ◽  
Zuogang Zhu ◽  
Langyou Wen ◽  
...  

2019 ◽  
Vol 149 (9) ◽  
pp. 2383-2389 ◽  
Author(s):  
Shiwei Liu ◽  
Jing Han ◽  
Qiong Wu ◽  
Bing Bian ◽  
Lu Li ◽  
...  

2002 ◽  
Vol 727 ◽  
Author(s):  
Tae-Sik Yoon ◽  
Ki-Bum Kim

AbstractGe-rich Si1-XGeX nanocrystals are formed by the selective oxidation of Si during the dry oxidation of an amorphous Si0.7Ge0.3 layer. The oxidation kinetics of the alloy film shows the activation energies of linear and parabolic rate constants are about 1.35 and 1.02 eV, respectively, based on the model proposed by Deal and Grove. In addition, as a result of the selective oxidation of Si and Ge pile-up during the oxidation process, Ge-rich Si1-XGeX nanocrystals are formed with the size of 5.6 ± 1.7 nm and the spatial density of 3.6×1011/cm2 at 600°C. At higher temperature of 700 and 800°C, the size of nanocrystal is increased to about 20 nm. The nanocrystals formation by oxidation is thought to be due to higher oxidation rate at grain boundary than at bulk grain. Therefore, the dependence of size on temperature is explained with the grain size determined by solid phase crystallization of amorphous film, oxidation rate, and grain growth.


2020 ◽  
Vol 850 ◽  
pp. 48-53
Author(s):  
Svetlana Chornaja ◽  
Svetlana Zhizhkuna ◽  
Jevgenija Vladiko ◽  
Reinis Drunka ◽  
Aija Krūmiņa

1.25 – 5wt%Pt/Al2O3, 1.25 – 5wt%Pd/Al2O3, 1wt%Pd/TiO2, 1 – 5wt%Pd/TiO2-NF, 1.25wt%Pt+1.25wt%Pd/Al2O3, 5wt%Pt/SiO2, 5wt%Pt/C catalysts were synthesised and tested in the selective oxidation of 1,2-propanediol by molecular oxygen. It was found that all catalysts were active in alkaline water solutions; lactic acid was obtained as the main product of the reaction. The conversion of 1,2-propandiol and the yield of lactic acid depended on the content of active metal in the catalysts. The most active for the oxidation of 1,2-propandiol were palladium-containing catalysts supported on TiO2 nanofibers (Pd/TiO2-NF). The highest 1,2-propanediol conversion (100 %) and lactic acid yield (96 %) were obtained using the 5wt%Pd/TiO2-NF catalyst at the following oxidation parameters: c0(1,2-propanediol) = 0.3 mol/L, P(O2) = 1 atm, n (1,2-propanediol)/n (Pd) = 500 mol/mol, t = 60 °C, c0(NaOH) = 1.5 mol/L.


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