Automatic regulation of hydrogen partial pressure using a proton conducting ceramic based on SrCeO₃

Electrochemical regulation of hydrogen partial pressure in flowing gas was examined using a proton-conducting ceramic tube made of Yb-doped SrCeO₃. Hydrogen partial pressure in the test gas was controlled by electrochemical hydrogen pump. When pumping current was controlled based on the Faraday's law, hydrogen content in the test gas with a constant flow-rate was well regulated, while change in flow-rate of the gas caused some deviation of hydrogen partial pressure from that desired. The pumping current could be determined in a self-correcting manner, which was efficient to regulate gas even with changes in flow-rate and/or initial hydrogen content in the gas.