Graphical Abstract: ChemistryOpen 4/2012

The study of spontaneous emergence of spatiotemporal patterns far from equilibrium or dissipative structures has become an increasingly growing interdisciplinary field of research. From a chemical point of view, the spatially varying properties are usually thought of as being composed of several individually reacting elements that are coupled among each other. Examples of well-studied systems are the celebrated Belousov–Zhabotinsky reaction, heterogeneous catalytic reactions, and electrochemical reactions. In all cases, pattern-forming systems are characterized by internal feedback loops and are mathematically described by nonlinear evolution equations. Feedback loops form especially easily in electrochemical systems, and, in fact, any electrochemical system can in principle display temporal symmetry breaking in the form of spontaneous current or potential oscillations in some parameter range when driven far from equilibrium. Pattern formation in electrochemical systems occurs at the electrode–electrolyte interface and results from the interplay between interfacial kinetics and transport processes parallel to the electrode surface. The interfacial region exchanges energy and mass with the bulk electrolyte and the system is kept far from equilibrium by a constant supply of electrical energy from the surroundings to the electrode as schematically shown in Figure 1. This supply usually comes from a potentiostat or a galvanostat. In the galvanostatic operation mode, the potential of the working electrode varies in order to keep a preset current value. In the potentiostatic operation mode, the potential of the working electrode is controlled with respect to a reference electrode. In the scheme depicted in Figure 1, the electroactive species A diffuses from the bulk solution to the elec-