Evaluation of Corrosion Resistance of Au Plated Titanium Bipolar Plates for PEM Water Electrolysis

Corrosion resistance and interfacial contact resistance （ICR） of titanium （Ti） bipolar plates for polymer electrolyte menbrane water electrolysis （PEMWE） with different Au plating thickness were evaluated by potentiostatic polarization in a sulfuric acid solution of pH 3.0. No dissolution of Ti was detected by the ICP-MS analysis （＜1μg dm－3） when the Au plating thickness was 0.3μm or more. In the case of Ti with Au plating thickness of 0.1μm, Ti dissolved in the plating defects which were confirmed by ULV-SEM observation. The ICR increased after polarization test for Ti without plating, but not for Au plated Ti even with thickness of 0.1μm. These results indicate that microdefects in the plating layer can be starting points of dissolution of substrate, but do not immediately affect the increase in ICR as far as most of the surface remains covered.