Ta and Ti Anti-passivation Interlayers for Oxygen-Evolving Anodes Produced by Cold Gas Spray

Abstract

Conventional electrodes for electrochemical oxygen evolution (OER) comprise titanium substrate, an anti-passivation interlayer, and a mixed metal oxide catalyst layer. We report the use of cold gas spray to deposit titanium and tantalum anti-passivation interlayers, directly on titanium, for OER applications. Accelerated electrochemical life tests show that 100% tantalum interlayers exceeded the performance of commercial state-of-the-art electrodes. Microscopy reveals that electrode failure, in the case of 100% tantalum interlayers, is primarily due to catalyst loss; in contrast, the typical failure mode for conventional electrodes of this type is passivation of the titanium substrate. These results highlight the effectiveness of cold gas spray tantalum for extending electrode lifetimes while maximizing catalyst utilization.