Modeling anisotropic chemical wave patterns in the NO+H2 reaction on a Rh(110) surface

A realistic mathematical model describing the formation of anisotropic chemical wave patterns in the NO + H-2 reaction on a Rh(110) surface is presented. For the point model describing the local reaction kinetics a bifurcation analysis has been conducted. In order to take into account the state-dependent anisotropy of surface diffusion site-blocking effects through coadsorbates for the diffusing species were introduced. The spatially distributed model reproduces well the experimentally determined excitability and bistability range and the existence ranges for the different types of chemical wave patterns: elliptical and rectangular target patterns, travelling wave fragments, and varying front geometries in the range of double metastability were modeled. In addition, the dependencies of the pulse/front velocity on the hydrogen partial pressure and temperature were simulated. (C) 2001 American Institute of Physics.