Observation of synchronized spatiotemporal reaction waves in coupled electrochemical oscillations of an NDR type

The coupling of spatiotemporal reaction waves was investigated by the use of current oscillations of an NDR type, appearing in H2O2 reduction on platinum (Pt) electrodes. For two Pt-ring working electrodes located side by side, the oscillatory coupling gave rise to various synchronized waves, such as spatially homogeneous waves (HW's) in an in-phase mode, HW's in an anti-phase mode, and a standing wave or a traveling wave synchronized with a HW, depending on the applied potential and the relative position of the reference electrode. The results are explained in terms of a combination of positive local coupling and negative global coupling effects.