3D Titania Nanotube Array Support for Water Electrolysis Palladium Catalysts

Abstract A critical step in developing deployable water electrolysis technologies is the reduction in the amount of platinum group metals (PGMs) that are the most active catalysts for hydrogen and oxygen evolution. In this paper, we demonstrate a convenient strategy to reduce the PGM loading in electrolysis by using ultra-low Pd loaded electrocatalysts supported on 3D architectures of titania (TiO2) nanotubes. This manuscript focuses on the following aspects: 1) a comprehensive analysis of the synthesis of the TiO2 support using water-based electrolytes; 2) the deposition of Pd catalyst to the support by either physical vapour deposition or dropcast and 3) functional characterisation of the obtained materials for hydrogen and oxygen evolution in both acidic and alkaline environments. A new strategy is developed to obtain short low aspect ratio 3D titania nanotubes arrays (TNTA) and we demonstrate that an extremely low quantity of Pd (81 µg cm−2) is sufficient to obtain significant activity improvement in an Anion Exchange Membrane (AEM) water electrolyser.