Electrodeposition of Platinum from Chloroplatinic Acid

Abstract

SYNOPSISThe electrodeposition of platinum from aqueous solutions containing chloroplatinic acid (15 to 25 g/l) and hydrochloric acid (10–390 g/l HCl) has been investigated at rates of deposition from about 0·1 to 1·1 × 10−3 in./hr and at temperatures from 45° to 75°C in a successful attempt to define the conditions for the production of ductile plates. The quality of the plates was assessed by microexamination, by their hardness and by a simple rolling test. The process was operated with platinum anodes, which behaved as soluble anodes in all electrolytes which were acid enough to yield ductile deposits. The plating cell was operated both with and without a diaphragm; the non-diaphragm cell was preferred because it was simpler to operate. The amount of stirring was critical; best results were obtained without any stirring except that provided by the thermal convection currents when the bath was at 60–70°C. Plating conditions could not be defined in terms of current density because the plating rate was aff...