3D titania nanotube array support for water electrolysis palladium catalysts. (1st July 2021)

• Record Type: Journal Article
• Authors: Bellini, M.; Berretti, E.; Innocenti, M.; Magherini, G.; Pagliaro, M.V.; Poggini, L.; Miller, H.A.; Lavacchi, A.; Vizza, F.
• Is Part Of: Electrochimica acta. Volume 383(2021)
• Publication Date: 2021-07-01
• Subjects: Titanium dioxide -- Nanotubes -- Palladium -- Electrolysis -- Electrocatalysis; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.138338
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: We demonstrate the growth of short nanotubes with low aspect ratio from water on titanium non-woven web. Magnetron sputtering is effective for the deposition of ultra-low Pd loadings on 3D TNTA. The ultra-low Pd loaded 3D TNTA delivers 0.3 A cm −2 @ 2 V and 1.485 A cm −2 @ 2.5 as cathode in an anion exchange membrane electrolyser. Performance does not change significantly after 24 h of operation at 1 A cm −2 at 60 °C. 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.