Water-Electrolysis Cells Using Hydrogen-Diffusion Cathodes
Report Number: AMRL TR 67-65
Author(s): Kolic, Edwin S., Clifford, John E.
Corporate Author(s): Battelle Memorial Institute
Laboratory: Aerospace Medical Research Laboratories
Date of Publication: 1967-11
Pages: 50
Contract: AF 33(615)-2954
DoD Project: 6373
DoD Task: 637302
Identifier: AD0664361
Abstract:
The feasibility of extended operation of palladium-silver alloy hydrogen-diffusion cathodes was demonstrated by essentially 100 percent hydrogen transmission for 486 days of operation at the following experimental conditions: 6.35-mm-OD x 0.013-mm-wall Pd-25Ag cathode tube at 37 ma/sq cm; free electrolyte cell with 22 ml of 60 percent NaOH at 145C; cell voltage of 1.74 +0.03 or -0.03 volts with solid cylindrical platinum anode. The determination of the maximum efficient current density (MECD) as a function of temperature indicated that satisfactory operation in the above run could have been obtained at temperatures as low as 112C; 53C with new cathode-activation treatments; or 30C with rhodium treatment of the cathode. In addition to platinum, platinum-10 rhodium alloy was shown to be a satisfactory anode material, but not gold. The feasibility of producing hydrogen gas at a pressure 15 psi higher than oxygen with only a slight decrease in MECD was demonstrated. New electrolyte preelectrolysis procedures were developed to counteract apparent purity variations in reagent-grade NaOH pellets. Of a number of possible matrix materials investigated, the longest satisfactory operation was obtained with fuel-cell asbestos: 280 hours at 70C and 37 ma/sq cm, but only 15 hours at 135C. The feasibility of using a free electrolyte of phosphoric acid was demonstrated in a 4-hour run at 37 ma/sq cm and 60C.
Provenance: RAF Centre of Aviation Medicine
Author(s): Kolic, Edwin S., Clifford, John E.
Corporate Author(s): Battelle Memorial Institute
Laboratory: Aerospace Medical Research Laboratories
Date of Publication: 1967-11
Pages: 50
Contract: AF 33(615)-2954
DoD Project: 6373
DoD Task: 637302
Identifier: AD0664361
Abstract:
The feasibility of extended operation of palladium-silver alloy hydrogen-diffusion cathodes was demonstrated by essentially 100 percent hydrogen transmission for 486 days of operation at the following experimental conditions: 6.35-mm-OD x 0.013-mm-wall Pd-25Ag cathode tube at 37 ma/sq cm; free electrolyte cell with 22 ml of 60 percent NaOH at 145C; cell voltage of 1.74 +0.03 or -0.03 volts with solid cylindrical platinum anode. The determination of the maximum efficient current density (MECD) as a function of temperature indicated that satisfactory operation in the above run could have been obtained at temperatures as low as 112C; 53C with new cathode-activation treatments; or 30C with rhodium treatment of the cathode. In addition to platinum, platinum-10 rhodium alloy was shown to be a satisfactory anode material, but not gold. The feasibility of producing hydrogen gas at a pressure 15 psi higher than oxygen with only a slight decrease in MECD was demonstrated. New electrolyte preelectrolysis procedures were developed to counteract apparent purity variations in reagent-grade NaOH pellets. Of a number of possible matrix materials investigated, the longest satisfactory operation was obtained with fuel-cell asbestos: 280 hours at 70C and 37 ma/sq cm, but only 15 hours at 135C. The feasibility of using a free electrolyte of phosphoric acid was demonstrated in a 4-hour run at 37 ma/sq cm and 60C.
Provenance: RAF Centre of Aviation Medicine