Langmuir-Hinshelwood Mechanism

2021 ◽  
pp. 1-1
Author(s):  
William M. Irvine
2010 ◽  
Vol 10 (2) ◽  
pp. 172-176
Author(s):  
Restu Kartiko Widi

Reaction kinetics for the oxidation of propane over diluted-leached MoVTeNb is described. This paper is focused on the study of products selectivity profile and determination of the orders of propane disappearance and propene formation. The result shows that selective oxidation of propane to propene over this catalyst follows the Langmuir-Hinshelwood mechanism. The disappearance of propane is first order with respect to hydrocarbon and partial order (0.21) with respect to oxygen. The propene formation is first order with respect to hydrocarbon and not depending on oxygen concentration.   Keywords: propane oxidation, propane disappearance, propene formation, kinetic, reaction order


2011 ◽  
Vol 324 ◽  
pp. 149-152
Author(s):  
Carlos Youssef ◽  
Eric Puzenat ◽  
Samir Najm ◽  
Nicole Jaffrezic-Renault ◽  
Chantal Guillard

TiO2P25 catalyst was used to study the photocatalytic oxidation of CO to CO2at 288K. Two parameters, O2and H2O were used to study its effect on the photocatalytic process. The dependency of the reaction rate on the CO concentration and water vapor was explained in terms of Langmuir-Hinshelwood mechanism. The presence of a high concentration of water vapor inhibits the CO photocatalytic oxidation at low oxygen concentration. We have noted an adsorption competition between CO and H2O on the TiO2active sites.


Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 288 ◽  
Author(s):  
Nigora Turaeva ◽  
Herman Krueger

The Wolkenstein’s theory of catalysis and the d-band theory of formation chemical bonds between transition metal catalysts and adsorbates were used to develop the approach applied to the kinetics of CO oxidation by gold nanoparticles. In the model, within the framework of the mechanism of the reaction going through dissociative adsorption of oxygen molecules and reaction with gas-phase CO molecules, weak and strong chemisorption states of intermediates (O, CO2) were taken into account in the kinetic equations by introducing reversible electronic steps corresponding to electron transfers between the intermediates and the catalyst. As a result, we obtain the expression for the reaction rate, which exhibits a volcano-shape dependence upon the size of the gold nanoparticles at the conditions when the intermediates fractions are not small compared to the empty active sites of the catalyst. It is supposed that the approach can be also applied to the Langmuir-Hinshelwood mechanism.


2020 ◽  
Author(s):  
Keisuke Iida ◽  
Yoshiharu Mukouyama

It is well accepted that adsorbed CO (COad) on Pt electrode reacts with water (or oxygenated species). We have recently found that COad also reacts with methanol and ethanol to form methyl formate (COad + CH3OH → HCOOCH3) and ethyl formate (COad + C2H5OH → HCOOC2H5), respectively, by using surface-enhanced infrared absorption spectroscopy and high-performance liquid chromatography. In the present report, we estimate the rate constants of the reactions by considering that the reactions proceed via Langmuir-Hinshelwood mechanism. The rate constants are estimated to be in the order of 0.1 s-1.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Muhammad Saeed ◽  
Muhammad Ibrahim ◽  
Majid Muneer ◽  
Nadia Akram ◽  
Muhammad Usman ◽  
...  

Abstract Here in, we report the synthesis and characterization of ZnO–TiO2 composite as a potential photo catalyst for photo degradation of methyl orange under UV irradiation. ZnO–TiO2 with 1:1 ratio was synthesized via wet incipient impregnation method using TiO2 and Zn(NO3)2 ⋅ 6H2O as precursor material and the prepared composite was characterized by XRD, EDX and SEM. The synthesized composite was employed as photo catalyst for photo degradation of methyl orange. The photo degradation results showed that ZnO–TiO2 exhibited better catalytic performance than ZnO and TiO2 alone. The methyl orange photo degradation efficiency was determined to be 98, 75 and 60% over ZnO–TiO2, ZnO and TiO2 respectively using 50 mL solution of 100 mg/L at 40 °C for 120 min. The ZnO–TiO2 catalyzed photo degradation of methyl orange followed pseudo-first-order kinetic in terms of Langmuir–Hinshelwood mechanism.


2019 ◽  
Vol 9 (21) ◽  
pp. 6085-6091 ◽  
Author(s):  
Jinyao Xiang ◽  
Xuesen Du ◽  
Yuyi Wan ◽  
Yanrong Chen ◽  
Jingyu Ran ◽  
...  

The heterogeneous SCR reaction obeys the well-known Eley–Rideal mechanism or Langmuir–Hinshelwood mechanism, while fast SCR over alkali-doping catalysts follows the another “E–R” mechanism with adsorbed NO2.


2018 ◽  
Vol 8 (4) ◽  
pp. 985-995 ◽  
Author(s):  
M. Faycal Atitar ◽  
Asmae Bouziani ◽  
Ralf Dillert ◽  
Mohamed El Azzouzi ◽  
Detlef W. Bahnemann

The Langmuir–Hinshelwood mechanism applies to the photocatalytic degradation of imazapyr only when assuming the occurence of light-induced changes of the photocatalyst surface affecting the adsorption of the probe molecule.


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