Crawford,
Graphite electrodes can be made from the carbon rods in an old fashioned
dry cell (D or C size), and the carbon does not react with most common
gasses you might generate. Platinum electrodes on the other hand are lower
in resistance and even less likely to react but not easily obtainable and
expensive.
Gary
Gary Karshner
St. Mary's University
San Antonio, Texas
KARSHNER@STMARYTX.EDU