Stanley H. Langer

Effect of dilute chloride ion on platinum electrodes

Abstract Surface oxide formation, in the presence of small concentrations of HCl has been studied in 2 N H 2 SO 4 by anodic oxidation and cathodic stripping on bright platinum and molded platinum black-polytetrafluoroethylene electrodes. At the lowest concentrations, −3 M , the principal effect at potentials less than 1.4 V appears to result from halide ion surface adsorption which prevents formation of the amount of surface oxide ordinarily observed. On platinum-black, the adsorption effect is considerable and results in significant decrease in electrochemically determined surface area at 1.24 V, based on surface oxide formation. As the concentration of HCl is increased to 10 −1 M , the sequence of surface oxide formation on bright platinum is changed and higher oxides (higher oxygen concentration at the surface) are not observed. Oxygen tends not to be held on the electrode surface. Chloride ion discharge potential is affected by current density and surface oxide formation on bright platinum electrodes.

Hydrogen: Electrolytic Technique for Purifying It and Removing It from a Gas Stream

Purified hiydrogen is obtained by impressing a potential gradient across a cell containintg two efficient electrodes separated by a barrier electrolyte phase and passing an impure hydrogen stream into the anode compartment. Power requirements are low and can be controlled through thle resistance of the electrolyte. The technique can also be used for pumping and accurate metering.