Towards Upscaling of La_5.5WO_11.25−δ Manufacture for Plasma Spraying-Thin Film Coated Hydrogen Permeable Membranes

• Main Authors: Sonia Escolástico, Cecilia Solís, Antonio Comite, Fiorenza Azzurri, Malko Gindrat, Stefan Moser, Johannes Rauch, Gregory Szyndelman, Rajiv Damani, Jose M. Serra
• Format: Article
• Language: English
• Published: MDPI AG 2020-08-01
• Series: Membranes
• Subjects: lanthanum tungstate; H₂ separation; ceramic protonic conductors; membrane reactors; low-pressure plasma spraying (LPPS-TF)
• Online Access: https://www.mdpi.com/2077-0375/10/9/192

Lanthanum tungstate (La₆WO₁₂) is a promising material for the development of hydrogen separation membranes, proton ceramic electrolyzer cells and protonic ceramic fuel cells due to its interesting transport properties and stability under different operation conditions. In order to improve the hydrogen transport through the La₆WO₁₂ membranes, thin membranes should be manufactured. This work is based on the industrial production of La_5.5WO_11.25−δ (LWO) powder by spray drying and the manufacturing of thin membranes by low-pressure plasma spraying (LPPS-TF) technique. LPPS-TF allows the production of dense thin films of high quality in an industrial scale. The powders produced by spray drying were morphological and electrochemically characterized. Hydrogen permeation fluxes of a membrane manufactured with these powders were evaluated and fluxes are similar to those reported previously for LWO powder produced in the lab scale. Finally, the transport properties of LWO thin films deposited on Al₂O₃ indicate that LPPS-TF produces high-quality LWO films with potential for integration in different applications.