جستجوی مقالات مرتبط با کلیدواژه « langmuir-hinshelwood model » در نشریات گروه « شیمی »

Pt/Zr(x)-HMS/HZSM-5 catalysts with various Si/Zr ratios (as x) were used for investigation of the kinetics of n-heptane reforming process under 350 - 450 oC reaction temperature, 35 to 80 ml min-1 flowing rate of hydrogen and 2 to 5 ml h-1 flowing rate of n-heptane. In the present work, two kinetics (power law and Langmuir - Hinshelwood) models were selected and examined to describe the kinetics of the n-heptane reforming process over the used catalysts. The results show that the Langmuir - Hinshelwood model provides a better fit with the experimental data and allows to determine the kinetics parameters. Among the synthesized catalysts, Pt/Zr(35)-HMS/HZSM-5 (with Si/Zr = 35) has the best performance for this process. Because this catalyst in contrast to others, based on the apparent activation energies, has a fast formation of aromatic and isomeric products, and low rate on the production of by-products, such as cracking and hydrogenolysis products.

The total oxidation of toluene at a wide temperature range (200–500 oC) over micro/mesoporous platinated catalysts has been investigated about activity, selectivity to CO2 and CO, catalyst's stability versus coke deposition and reaction kinetics. Kinetic of toluene oxidation was measured under various oxygen and toluene pressures and also the effect of the reaction conditions on the catalytic performance was studied. For more study, two kinetic models have also been selected and tested to describe the kinetics for this reaction. The results show that the Langmuir-Hinshelwood model provides a good fit for the experimental data. The obtained results showed that Pt/HZSM-5(30)-HMS have a better ability than other catalysts for the oxidation reaction of toluene, such as maximum toluene conversion (>97%), high selectivity to CO2 (100%), good catalytic stability against coke deposition and appropriate kinetic parameters