Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Square chemical waves in the catalytic reaction NO + H2 on a rhodium(110) surface


Mertens,  F.
Fritz Haber Institute, Max Planck Society;


Imbihl,  Ronald
Physical Chemistry, Fritz Haber Institute, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Mertens, F., & Imbihl, R. (1994). Square chemical waves in the catalytic reaction NO + H2 on a rhodium(110) surface. Nature, 370, 124-126. doi:10.1038/370124a0.

Cite as: https://hdl.handle.net/21.11116/0000-0009-A29F-D
IT WAS realized as early as 19061 that coupling between an autocatalytic reaction and the diffusion of the autocatalytic component can give rise to a propagating reaction front—a chemical wave. Chemical waves have been studied intensively in fluid-phase reaction–diffusion systems2, but in recent years a variety of spatiotemporal patterns has also been observed for oscillatory reactions on single-crystal surfaces3,4. One important new aspect that has been introduced by these studies is that of anisotropic diffusion, as a consequence of the fixed surface geometry on which the diffusion of the adsorbed particles takes place. Here we report the observation of a transition from elliptical to square-shaped concentric chemical waves in the reaction of NO and H2 on a rhodium(HO) surface. The elliptical pattern is characteristic of simple anisotropic diffusion, but we attribute the origin of the square pattern to a state-dependent anisotropy—that is an anisotropy that varies along the wave profile as changes in the adsorbate coverage generate different reconstructions of the substrate structure. This interplay between diffusional anisotropy and the state of the system can be expected to be quite general and to give rise to new varieties of oscillatory patterning.