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Platinum kinetic model

Darling RM, Meyers JP. 2003. Kinetic model of platinum dissolution in PEMPCs. J Electrochem Soc 150 A1523-A1527. [Pg.308]

Andreaus B, Maillard F, Kocylo J, Savinova ER, Eikerling M. 2006. Kinetic modeling of COad monolayer oxidation on carbon-supported platinum nanoparticles. J Phys Chem B 110 21028-21040. [Pg.454]

Co-limited kinetics with a significant utilization region. As with platinum, the model predicts that the chemical portion of the reaction will be co-limited by molecular dissociation and transport. Values of k calculated from the model for the analyzed conditions vary from 0.4 to 20 gvc depending on Pq2 temperature, and electrode surface area, with typical values in the 3—5 gm range. This result indicates that a significant portion of the electrode surface is active for oxygen reduction, which explains Takeda s (and other s) observation that the performance of LSG electrodes on YSZ improves with thickness up to a... [Pg.572]

Over 30 man-years of effort were involved in developing the model, which is named KINPTR, an acronym for kinetic platinum reforming model. Since its development, KINPTR has had a major impact in Mobil s worldwide operations. It can be accessed by personnel at each of Mobil s locations throughout the world. Input requirements are simple and convenient making it very user friendly. Only feed characteristics, product quality targets, process configuration information, and process conditions are required for input. Output is informative and detailed. Overall and detailed yields, feed and product properties, and reactor performance data are given in the output. [Pg.194]

It should be said that at present the available literature concerning the kinetic models which account for the topochemical character of catalyst surface processes is limited, but reference can be made to refs. 119 and 120. In ref. 119, a kinetic model for the oxidation of hydrogen on platinum is... [Pg.74]

The results show that the specificities of catalyst deactivation and it s kinetic description are in closed connection with reaction kinetics of main process and they form a common kinetic model. The kinetic nature of promotor action in platinum catalysts side by side with other physicochemical research follows from this studies as well. It is concern the increase of slow step rate, the decrease of side processes (including coke formation) rate and the acceleration of coke transformation into methane owing to the increase of hydrogen contents in coke. The obtained data can be united by common kinetic model.lt is desirable to solve some problems in describing the catalyst deactivation such as the consideration of coke distribution between surfaces of metal, promoter and the carrier in the course of reactions, diffusion effects etc,. [Pg.548]

Table 1 presents several examples of unsteady-state kinetics models. These models are presented in the form of rate dependencies for catalytic reaction stages and side processes. The parameters of the models, such as reaction rate constants and activation energies, are given in references (Table 1) and were determined mainly from experimental data using transient response techniques. For the reaction of CO oxidation over a supported platinum catalyst, the kinetic gas theory was applied for estimating the adsorption constants. [Pg.492]

Figure 68. The exchange current density as a function of oxygen partial pressure for different temperatures confirming the electrode kinetical model given in the text.256 (Reprinted from D. Y. Wang, A. S. Nowick, Cathodic and Anodic Polarization Phenomena at Platinum Electrodes with Doped CeC>2 as Electrolyte. I. Steady-State Overpotential. , J. Electrochem. Soc., 126, 1155-1165. Copyright 1979 with permission from The Electrochemical Society, Inc.)... Figure 68. The exchange current density as a function of oxygen partial pressure for different temperatures confirming the electrode kinetical model given in the text.256 (Reprinted from D. Y. Wang, A. S. Nowick, Cathodic and Anodic Polarization Phenomena at Platinum Electrodes with Doped CeC>2 as Electrolyte. I. Steady-State Overpotential. , J. Electrochem. Soc., 126, 1155-1165. Copyright 1979 with permission from The Electrochemical Society, Inc.)...
R. M. Darling, and J. P. Meyers, Kinetic model of platinum dissolution in PEM fuel cells in E. Society (Ed.), Proton Conducting Membrane Fuel Cells III, 2005, p. 44. [Pg.395]

R. M. Darling and J. P. Meyers, "Kinetic Model of Platinum Dissolution in PEMFCs," Journal of the Electrochemical Society, 150 (2003) A1523-A1527. [Pg.517]

A kinetic model was developed for the experimental conditions shown in Table 2 and was based on the reaction steps listed in Table 3, where o denotes the stoichiometric number of the reaction steps [23]. A denotes a noble metal site, where no distinction is made between platinum and rhodium. Although 10 kPa H2O and 10 kPa CO2 was fed during the experiments, their influence is not explicitly taken into account in the elementary reaction steps. The latter is justified because at 10 kPa the partial reaction orders in H2O and CO2 are both approximately zero, as can be seen in Figure 2. [Pg.394]

From kinetic modeling of ethanol oxidation on platinum. Van den Tillaart et al. [Pg.492]

A detailed computational model was developed for several different iimovative designs for the preferential carbon monoxide (CO) oxidation reactor using a kinetic mechanism and reaction sequence derived from a micro-kinetic model and literature data for the specific adsorption coefficients and kinetic parameters for a platinum-based catalyst. [Pg.323]

In the case of chitosan derivatives, noble metal ions are sorbed according to several kinetic models based on pure sorption, pure reduction and dual sorption-reduction mechanisms [149, 150]. Moreover, the optimum acid pH for noble metal ions sorption depends on the metal. For platinum and palladium, it was equal to 2. For CS cross-linked by glutaraldehyde (CS-GA) for... [Pg.21]

Pleasantly, this kinetic modeling enables us to extract interesting features of this catalytic system, for example, platinum species distribution over time, catalyst loading or temperature effects on products distribution and reaction rates, and so on, thereby demonstrating its practical usefulness [16,23a]. [Pg.156]

To model the performance of the autothermal reformer, kinetics from the literature that had been determined for the catalytic combustion of methane over a platinum-based catalyst and for steam reforming over nickel-based catalyst were combined and fitted to the experimental data of Flytzani-Stephanopoulos et al. [153]. The water-gas shift reaction was assumed to reach thermodynamic equilibrium under all conditions in the reformer reactor, which is usually the case in reformers. Methane formation was not considered. Because catalyst pellets had been used for the determination of the kinetics, diffusion limitations were to be expected. They had been lumped into the kinetic models. The hot spot formation usually observed at... [Pg.197]

Rebrov EV, de Croon MHJM, Schouten JC (2002) Development of the kinetic model of platinum catalyzed ammonia oxidation in a microreactor. Chem Eng J 90 (l-2) 61-76 Colombo M, Nova I, Tronconi E, SchmeiBer V, Bandl-Konrad B Experimental and modeling study of a dual-layer (SCR -I- PGM) NH3 slip monolith catalyst (ASC) for automotive SCR aftertreatment systems. Part 1. Kinetics for the PGM component and analysis of SCR/PGM interactions Appl Catal, B. 142-143 (2013) 861-876... [Pg.585]


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Kinetic platinum reforming model

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