Abstract: An electrochemical device, such as a fuel cell, and method of forming it, in which electrodes, such as anode and cathode, are disposed on a semipermeable or permeable membrane having ion conduction channels. Electrocatalyst is deposited on locations on the electrodes limited to and corresponding to the ion conduction channels. In a first embodiment, anode and cathode electrodes sandwich the membrane, a counter electrode is connected to one of the electrodes, electrolyte containing an electrochemical precursor to the electrocatalyst is applied to the other electrode whereby, upon applying current to the counter electrode, electrocatalyst is deposited on locations on the first electrode corresponding to the ion conduction channels. The process is repeated with the counter electrode connected on the other electrode of the cell. In a second embodiment, a combination of a first electrode and a first membrane is assembled as is a combination of a second electrode and a second membrane.