TITLE

Analysis of concentration and temperature patterns on catalytic surfaces

AUTHOR(S)
Colin, Pierre; Balakotaiah, Vemuri
PUB. DATE
April 1994
SOURCE
Journal of Chemical Physics;4/1/1994, Vol. 100 Issue 7, p5338
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
A simple mathematical model for pattern formation on isothermal as well as nonisothermal catalytic surfaces is developed and analyzed. The model accounts for diffusion of the species, conduction of heat, convection from the fluid phase, and a bimolecular Langmuir–Hinshelwood type kinetic expression. The isothermal model is shown to exhibit stationary concentration patterns for typical sets of parameters. The nonisothermal model exhibits stationary temperature and concentration patterns only for near stoichiometric composition of the reactants (three equation model). The calculations show that these stationary patterns exist in regions near the ignition and extinction points and are most likely to form during ignition or extinction of the surface. It is also found that moving concentration and temperature patterns exist near the Hopf bifurcation point of the ignited homogeneous branch. The moving patterns predicted for realistic values of the transport and kinetic parameters are concentration patterns with almost constant temperature distribution on the surface. The typical size of the patterns and the period of oscillation are estimated in terms of the physicochemical parameters.
ACCESSION #
7609887

 

Related Articles

  • Vibrational phase relaxation at surfaces: The role of lateral interaction. Persson, B. N. J.; Hoffmann, F. M. // Journal of Chemical Physics;3/1/1988, Vol. 88 Issue 5, p3349 

    We have studied the temperature and coverage dependence of the vibrational line shape of the C–O stretch vibration for CO on Ru(001). We find that the narrow IR line profile which is observed for the ordered structure of CO on Ru(001) is due to the strong dipole–dipole coupling and...

  • The influence of surfaces on vapor pressures. Searcy, Alan W. // Journal of Chemical Physics;9/15/1985, Vol. 83 Issue 6, p3095 

    An analysis of internal particle equilibrium in J. Chem. Phys. 81, 2489 (1984) is generalized by means of Lagrange’s method of undetermined multipliers to show that a one-component crystalline particle of fixed size and shape is at equilibrium at constant temperature and pressure when the...

  • CO desorption kinetics from clean and sulfur-covered Ru(001) surfaces. Brand, J. L.; Arena, M. V.; Deckert, A. A.; George, S. M. // Journal of Chemical Physics;4/1/1990, Vol. 92 Issue 7, p4483 

    The desorption of CO from clean and sulfur-covered Ru(001) surfaces was studied using laser-induced thermal desorption (LITD) and temperature programmed desorption (TPD) techniques. CO was observed to desorb from clean Ru(001) with coverage-dependent kinetics. The isothermal desorption of CO was...

  • Ab initio potential and variational transition state theory rate constant for H-atom association with the diamond (111) surface. de Sainte Claire, Pascal; Barbarat, Philippe; Hase, William L. // Journal of Chemical Physics;8/1/1994, Vol. 101 Issue 3, p2476 

    High-level ab initio calculations were performed to determine accurate analytic potential energy functions for interactions a gas-phase H-atom has with H-atoms attached to the diamond (111) surface and with C-atom radical sites on this surface. The nonbonded potential between the gas-phase...

  • Effects of panel density, panel temperature, and cutter sharpness during edge machining on the roughness of the surface and profiled areas of medium density fiberboard. Akbulut, Turgay; Koç, Enüs // Forest Products Journal;Dec2004, Vol. 54 Issue 12, p67 

    The success of direct painting and thin laminating of profiled medium density fiber-board (MDF) is dependent upon the smoothness of surfaces and profiled areas. Many variables can affect surface smoothness or roughness. In this study, the effect of panel density, panel temperature, and cutter...

  • Rate of Unsteady Evaporation of a Spherical Drop with Regard to Concentration and Temperature Discontinuities at Its Surface. Yalamov, Yu. I.; Kuzmin, M. K. // Technical Physics;Mar2005, Vol. 50 Issue 3, p314 

    Unsteady evaporation and condensation growth of a quiescent spherical drop are studied in the case when the surface temperature and the saturated vapor concentration on the surface of the drop are variable and experience a jump in the Knudsen layer. A general (i.e., valid for any time scale)...

  • An Evaluation of the Strength of Land–Atmosphere Coupling. Dirmeyer, Paul A. // Journal of Hydrometeorology;Aug2001, Vol. 2 Issue 4, p329 

    Two ensembles of 1-month integrations of a coupled land–atmosphere climate model that differ only in their treatment of land surface boundary conditions have been generated from initial conditions chosen from the July states taken from each year of a 17-yr integration from the second...

  • Spatial and temporal patterns of land surface fluxes from remotely sensed surface temperatures within an uncertainty modelling framework. McCabe, M. F.; Kalma, J. D.; Franks, S. W.; Montanari, A. // Hydrology & Earth System Sciences;2005, Vol. 9 Issue 5, p467 

    Characterising the development of evapotranspiration through time is a difficult task, particularly when utilising remote sensing data, because retrieved information is often spatially dense, but temporally sparse. Techniques to expand these essentially instantaneous measures are not only...

  • Depression of Curie temperature by surface structural phase transition. Ho, H. Y.; Chen, Y. J.; Hwang, E. J.; Yu, S. K.; Shern, C. S. // Applied Physics Letters;4/2/2007, Vol. 90 Issue 14, p142505 

    The comparative study in structural properties for the mirror systems, 1 ML Ni/1 ML Co/Pt(111) and 1 ML Co/1 ML Ni/Pt(111) surface ordered alloys, reveals a structural phase transition from NixCo1-xPt to NixCo1-xPt3 ordered surface alloy when the annealing temperature is between 750 and 800 K....

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics