Rotating temperature pulse during hydrogen oxidation on a nickel ring

Reaction-diffusion interactions generate spatiotemporal patterns in a variety of uniformly active chemical media. It is of interest to know how these patterns are affected by media nonuniformity. Here, we report the first observation of a rotating temperature pulse on a nonuniformly active (i.e., polycrystalline) surface of a nickel ring during atmospheric hydrogen oxidation. The pulse had an amplitude of about 100 ^∘{}C and completed one cycle around the ring every 565 s. Its width, velocity, and maximum temperature changed during each cycle, but were constant at a given position.