The Experts below are selected from a list of 23067 Experts worldwide ranked by ideXlab platform
Reinout Meijboom - One of the best experts on this subject based on the ideXlab platform.
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catalytic activity of mesoporous cobalt oxides with controlled porosity and crystallite sizes evaluation using the reduction of 4 nitrophenol
Applied Catalysis B-environmental, 2016Co-Authors: Batsile M Mogudi, Phendukani Ncube, Reinout MeijboomAbstract:Abstract Mesoporous cobalt oxides were synthesized using an inverse surfactant micelle method. The prepared materials are mono-dispersed nanoparticle aggregates with connected, well defined intra-particle voids. Powder X-ray diffraction, N2 sorption, scanning electron microscopy and transmission electron microscopy revealed that both pore and nanoparticle sizes are enlarged with thermal treatment temperatures. Nitrogen sorption experiments revealed that the pore diameters increased from 12.1 to 31.9 nm with the final heat treatment increase from 150 to 550 °C. The reduction of 4-nitrophenol has been chosen as a well-controlled model reaction allowing us to determine the catalytic activity as a function of crystallite size and pore diameter. A comparison of the various cobalt oxide catalysts is made in terms of Langmuir-Hinshelwood Kinetics.
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catalytic evaluation of dendrimer templated pd nanoparticles in the reduction of 4 nitrophenol using langmuir hinshelwood Kinetics
Applied Surface Science, 2014Co-Authors: Jihyang Noh, Reinout MeijboomAbstract:Abstract This study aimed to produce well-defined palladium nanoparticles using a dendrimer template technique and investigate their catalytic behavior through intensive kinetic evaluation using 4-nitrophenol (4-Nip) reduction as a model reaction. Three dendrimers, generation 4, 5, and 6 hydroxyl terminated poly(amidoamine) dendrimers, G4-OH, G5-OH, and G6-OH were used as templates, while metal to dendrimer ratios of 40, 80, and 160 were used for the G4-OH, G5-OH, and G6-OH dendrimers, respectively. The average diameters obtained for dendrimer-templated G4-OH(Pd40), G5-OH(Pd80), and G6-OH(Pd160) nanoparticles were 2.35 ± 0.58 nm, 2.02 ± 0.45 nm, and 2.21 ± 0.31 nm, respectively. Kinetic evaluation of the 4-Nip reduction catalyzed by the Pd nanoparticles was performed under various experimental conditions, such as various concentrations of the catalysts, 4-Nip, NaBH4, and various temperatures. The highest catalytic activity was obtained by using G6-OH(Pd160) catalyst. The adsorption equilibrium constants of 4-Nip (KNip) and borohydride ( K B H 4 − ) obtained by data fitting to the Langmuir–Hinshelwood equation as well as the activation parameters such as enthalpy of activation (ΔH‡), entropy of activation (ΔS‡), and activation energy (EA) obtained by Eyring and Arrhenius equations are reported.
Vasanth K Kumar - One of the best experts on this subject based on the ideXlab platform.
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langmuir hinshelwood Kinetics a theoretical study
Catalysis Communications, 2008Co-Authors: Vasanth K Kumar, K. Porkodi, Fernando RochaAbstract:Abstract The present study reports that it is impossible and inappropriate to approximate the Langmuir–Hinshelwood Kinetics to zero order Kinetics.
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constrain in solving langmuir hinshelwood kinetic expression for the photocatalytic degradation of auramine o aqueous solutions by zno catalyst
Dyes and Pigments, 2007Co-Authors: Vasanth K Kumar, K. Porkodi, A. SelvaganapathiAbstract:Abstract Langmuir–Hinshelwood (L–H) and first-order expressions are the most widely used expressions to explain the Kinetics of heterogeneous catalytic system. Previously lot of researchers approximated the L–H kinetic expression to first-order expression just to easily obtain the parameters involved in the L–H expression. However, it is inappropriate to alter a kinetic model, which is having definite assumptions behind it without any validation. This study reports the constrain in approximating the L–H kinetic expression to first-order kinetic expression using the experimental kinetic data of photocatalytic degradation of Auramine O aqueous solution in the presence of ZnO catalyst. Further, the present investigation showed that it is not appropriate to approximate the Langmuir–Hinshelwood Kinetics to first-order Kinetics. In addition, a second-order kinetic model is proposed and is found to well represent the experimental data of Auramine O degradation by ZnO catalyst for the range of initial dye concentration studied.
K. Porkodi - One of the best experts on this subject based on the ideXlab platform.
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langmuir hinshelwood Kinetics a theoretical study
Catalysis Communications, 2008Co-Authors: Vasanth K Kumar, K. Porkodi, Fernando RochaAbstract:Abstract The present study reports that it is impossible and inappropriate to approximate the Langmuir–Hinshelwood Kinetics to zero order Kinetics.
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constrain in solving langmuir hinshelwood kinetic expression for the photocatalytic degradation of auramine o aqueous solutions by zno catalyst
Dyes and Pigments, 2007Co-Authors: Vasanth K Kumar, K. Porkodi, A. SelvaganapathiAbstract:Abstract Langmuir–Hinshelwood (L–H) and first-order expressions are the most widely used expressions to explain the Kinetics of heterogeneous catalytic system. Previously lot of researchers approximated the L–H kinetic expression to first-order expression just to easily obtain the parameters involved in the L–H expression. However, it is inappropriate to alter a kinetic model, which is having definite assumptions behind it without any validation. This study reports the constrain in approximating the L–H kinetic expression to first-order kinetic expression using the experimental kinetic data of photocatalytic degradation of Auramine O aqueous solution in the presence of ZnO catalyst. Further, the present investigation showed that it is not appropriate to approximate the Langmuir–Hinshelwood Kinetics to first-order Kinetics. In addition, a second-order kinetic model is proposed and is found to well represent the experimental data of Auramine O degradation by ZnO catalyst for the range of initial dye concentration studied.
Fernando Rocha - One of the best experts on this subject based on the ideXlab platform.
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langmuir hinshelwood Kinetics a theoretical study
Catalysis Communications, 2008Co-Authors: Vasanth K Kumar, K. Porkodi, Fernando RochaAbstract:Abstract The present study reports that it is impossible and inappropriate to approximate the Langmuir–Hinshelwood Kinetics to zero order Kinetics.
Jt Johan Padding - One of the best experts on this subject based on the ideXlab platform.
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Towards a particle based approach for multiscale modeling of heterogeneous catalytic reactors
Chemical Engineering Science, 2019Co-Authors: Aditya Sengar, J.a.m. Kuipers, R.a. Van Santen, Jt Johan PaddingAbstract:Particle based approaches are one of the recent modeling techniques to overcome the computational limitation in multiscale modeling of complex processes, for example a heterogeneous catalytic reactor. We propose an efficient model for a chemical reactor where hydrodynamics of the solvent is determined by Stochastic Rotation Dynamics and a reaction occurs over a catalytic surface where the reaction Kinetics follows the mean-field assumption. We highlight the modeling techniques required to simulate such a system and then validate the model for its separate and combined components of convection, diffusion and reaction(s). A dimensionless analysis helps compare processes occurring at different scales. We determine the Reynolds number, Re, and the Damkohler numbers, Da and DaL in terms of key quantities. The approach is then used to analyse a reaction (a) following the Langmuir-Hinshelwood Kinetics, (b) generating product particles with different self-diffusivity values as compared to the reactant particles. The model developed can further incorporate reactions occurring inside complex geometries (pore diffusion) and also be used to study complex reaction systems for which the mean-field assumption is no longer valid.
