Kinetics of the catalytic oxidation of model compounds of lignin with hydrogen peroxide in the presence of peroxidase from horse-radish

2010 ◽  
Vol 84 (9) ◽  
pp. 1511-1515
Author(s):  
K. G. Bogolitsyn ◽  
M. A. Aizenshtadt ◽  
A. N. Pryakhin ◽  
V. V. Lunin ◽  
S. A. Pokryshkin
2003 ◽  
Vol 47 (1) ◽  
pp. 179-184 ◽  
Author(s):  
J.S. Park ◽  
H. Choi ◽  
K.H. Ahn

The sorption and catalytic oxidation of model compounds (pCBA and phenanthrene) and NOM on FeOOH were investigated using hydrogen peroxide and ozone, respectively. After oxidation with ozone, the hydrophobic, transphilic, and hydrophilic NOM fractions were isolated using XAD-8 and -4 resins to analyze the reaction characteristics. The sorption of pCBA was strongly dependent upon the pH, but phenanthrene exhibited a sorption behavior that was independent of the pH. In the case of NOM, the hydrophobic portion showed higher sorption affinity than hydrophilic and transphilic at pH 7.2. The concentrations of model compounds and oxidants were measured during the oxidations and the efficiency was compared for tests done with ozone alone and those using catalytic ozonation. Through the comparison of the sorption and decomposition of the model compounds, along with the effects of bicarbonate addition, mechanisms for catalytic oxidation with hydrogen peroxide or ozone were proposed, respectively.


1979 ◽  
Vol 44 (10) ◽  
pp. 2893-2903 ◽  
Author(s):  
Eva Schwertnerová ◽  
Dana M. Wagnerová ◽  
Josef Vepřek-Šiška

Catalytic oxidation of salicylic acid by molecular oxygen, induced by the oxidation of ascorbic acid, leads to the formation of a mixture of isomers of dihydroxybenzoic acid. The reaction is catalyzed by a series of metal chelates, especially Fe(II) and Co(II), the most marked catalytic effect having been found in the case of tetrasulphophthalocyanine of cobalt (CoTSP). The kinetics of the oxidation of ascorbic acid in the presence of salicylic acid was followed, and the formation of hydrogen peroxide as reaction intermediate was proved.


2016 ◽  
Vol 51 (6) ◽  
pp. 673-678
Author(s):  
I. M. Borisov ◽  
Z. Sh. Gazizova ◽  
R. S. Luksha ◽  
A. V. Baiburtli ◽  
I. S. Faizrakhmanov

2013 ◽  
Vol 641-642 ◽  
pp. 215-218
Author(s):  
Sheng Guo ◽  
De Yi Huang ◽  
Ji Feng She ◽  
Xiang Qun Liang

The bleaching efficiency of hydrogen peroxide can be promoted by using suitable activator. In our research, two methods were applied to compare the activating ability of three activators, TAED (tetraacetylethylenediamine), acetamide and dicyandiamide. The first part was hydrogen peroxide bleaching. TAED was excellent, because the brightness improvement was the maximum; the viscosity was acceptable. Acetamide was an applied activator in peroxide bleaching,for it could get same effects as TAED if the bleaching process had enough time and enough dosage. In the last part our study was about the kinetics of a lignin model compounds, acetovanillone, in peroxide-alone system, TAED/H2O2 system, acetamide/H2O2 system and dicyandiamide/H2O2 system. The rate constant, k and half-life period, t1/2 can be used to compare the rate of oxidation of acetovanilone. Compared to peroxide-alone system, three systems with activator and H2O2 could accelerate the reactions of hydrogen peroxide and acetovanillone. The t1/2 of TAED/H2O2 system was least of them. It was just 1/5 of t1/2 of peroxide-alone system, 1/4 of t1/2 of acetamide/H2O2 system and dicyandiamide/H2O2 system. The activating ability order of activators was: TAED> acetamide> dicyandiamide.


2021 ◽  
Vol 509 ◽  
pp. 111638
Author(s):  
Satyajit Dey Baruah ◽  
Subrata Paul ◽  
Nand Kishor Gour ◽  
Nishant Biswakarma ◽  
Ramesh Chandra Deka

Studies of the catalytic oxidation of benzene to maleic anhydride and carbon dioxide over vanadia/molybdena catalysts show that the major part of the reaction involves interacting gas and gas-solid processes. The results are consistent with a mechanism in which a benzeneoxygen adduct is formed catalytically, desorbs and then reacts to give maleic anhydride entirely in the gas phase. On the basis of this proposed mechanism, the kinetics of individual reactions have been investigated in some depth. The over-oxidation of maleic anhydride has been found to be not significant under the conditions of reaction. The kinetic relationships governing the homogeneous decomposition of the adduct and the oxidation of the adduct to maleic anhydride and to carbon dioxide have been established. The results show that essentially all of the anhydride originates from mixed gas-solid/gas reaction while substantial amounts of carbon dioxide are produced entirely catalytically.


Sign in / Sign up

Export Citation Format

Share Document