In the present work the electrochemical pattern formation was investigated during electro-oxidation of formic acid on platinum electrode. The working electrode is quasi-one-dimensional ribbon polycrystalline platinum. The stationary domains (sDs) have been successfully captured after an external pulse was triggered. At a relatively high conductivity a new kind of electrochemical pattern was found and it is named as cyclopean pattern. In a nonlinear electrochemical system with an N-type negative differential resistance, the theoretical simulation of the spatial temporal structure is able to predict the existence of stationary domains. Increasing the electrolyte conductivity promotes the formation of stationary domains and cyclopean pattern. The difference of the potential amplitudes in two phases (domains) becomes smaller in an electrolyte with a higher conductivity. (C) 2007 Elsevier Ltd. All rights reserved.