Electrochemical reactions can generate complex spatiotemporal patterns due to the inherent nonlinearities in the reaction kinetics, which often couple with various mass transfer and electrical coupling effects. We explore spatiotemporal pattern formation using multielectrode arrays embedded in flow channels. The kinetic equations are expressed as a superposition of local kinetics with a network of electrical coupling due to ohmic potential drops in the electrolyte. The networks are revealed by analysis of the synchronization patterns with the use of an oscillatory chemical reaction (nickel electrodissolution) and are further confirmed by direct decoding using phase model analysis. In dual electrode configuration, a variety coupling schemes, (uni- or bidirectional positive or negative) were identified depending on the relative placement of the reference and counter electrodes (e.g., placed at the same or the opposite ends of the ow channel). The synchronization patterns and the network configuration are compared for the linear and the branched channel configurations. With straight channel and multiple electrodes, a scale-free network was formed. With branched channels, the global to local coupling can be changed by the position of electrodes in the channel, and introduction of different concentration of electrolyte can mediate coupling between only the downstream electrodes. In fluidic network with cross channels, nonlinearity can be induced by obstacles in the channel which open ways to investigate the Braess’s paradox. The networked, electrode potential (current) spike generating electrochemical reactions hold potential for construction of an in-situ information processing unit to be used in electrochemical devices in sensors and batteries.