Okay. That helps some. It looks like you need something with precision to 0.01V or better. In the table that you listed, I assume this is taken from another experiment. To me, it looks like they controlled the voltage (0.1V steps) and the current density and reaction are just measured. Normally, you control one thing (volts, amps, or resistance). Ohm's Law relates everything to what you did change. For the current density, it was likely calculated be measuring the current (amps) and dividing that by the electrode area.
I do have a bit of a chemistry background. It is not my specialty, but physics/engineering undergraduate and graduate work had me involved to some extent in all of the physical sciences.