THE IMPACT OF THE OPERATION MODE ON PATTERN-FORMATION IN ELECTRODE-REACTIONS - FROM POTENTIOSTATIC TO GALVANOSTATIC CONTROL

Applying a constant voltage across an external resistor in series with , an electrochemical cell allows the continuous variation of the exper imental control mode from potentiostatic to galvanostatic. The model f or electrochemical pattern formation presented for potentiostatic cond itions in Ref. 1 is extended to account for this general case. The res istor introduces a global coupling into the model, interacting in a no ntrivial manner with the nonlocal coupling through migration currents in the electrolyte which occur independently of the control mode. The complex interplay of these two coupling terms is investigated as a fun ction of operating parameters, and is illustrated by simulations in th e bistable regime of an electrochemical reaction.