Modeling anisotropic chemical wave patterns in the NO+H-2 reaction on a Rh(110) surface

A realistic mathematical model describing the formation of anisotropic chem ical wave patterns in the NO + H-2 reaction on a Rh(110) surface is present ed. For the point model describing the local reaction kinetics a bifurcatio n analysis has been conducted. In order to take into account the state-depe ndent anisotropy of surface diffusion site-blocking effects through coadsor bates for the diffusing species were introduced. The spatially distributed model reproduces well the experimentally determined excitability and bistab ility range and the existence ranges for the different types of chemical wa ve patterns: elliptical and rectangular target patterns, travelling wave fr agments, 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 Amer ican Institute of Physics.