Mixed proton and electron conducting double perovskite anodes for stable and efficient tubular proton ceramic electrolysers
[EN] Hydrogen production from water electrolysis is a key enabling energy storage technology for the large-scale deployment of intermittent renewable energy sources. Proton ceramic electrolysers (PCEs) can produce dry pressurized hydrogen directly from steam, avoiding major parts of cost-driving downstream separation and compression. However, the development of PCEs has suffered from limited electrical efficiency due to electronic leakage and poor electrode kinetics. Here, we present the first fully operational BaZrO3-based tubular PCE, with 10 cm(2) active area and a hydrogen production rate above 15 Nml min(-1). The novel steam anode Ba1-xGd0.8La0.2+xCo2O6-delta exhibits mixed p-type electronic and protonic conduction and low activation energy for water splitting, enabling total polarization resistances below 1 Omega cm(2) at 600 degrees C and Faradaic efficiencies close to 100% at high steam pressures. These tubular PCEs are mechanically robust, tolerate high pressures, allow improved process integration and offer scale-up modularity. ; The work leading to these results has received funding from the Research Council of Norway (grant 236828) and from the European Union's Seventh Framework Programme (FP7/2007-2013) for the Fuel Cells and Hydrogen Joint Technology Initiative under grant agreement 621244 ('ELECTRA') and Fuel Cells and Hydrogen 2 Joint Undertaking under grant agreement 779486 ('GAMER'). This Joint Undertaking receives support from the European Union's Horizon 2020 research and innovation programme, Hydrogen Europe and Hydrogen Europe research. ; Vøllestad, E.; Strandbakke, R.; Tarach, M.; Catalán-Martínez, D.; Fontaine, M.; Beeaff, D.; Clark, DR. (2019). Mixed proton and electron conducting double perovskite anodes for stable and efficient tubular proton ceramic electrolysers. Nature Materials. 18(7):752-759. https://doi.org/10.1038/s41563-019-0388-2 ; S ; 752 ; 759 ; 18 ; 7 ; Hauch, A., Ebbesen, S. D., Jensen, S. H. & Mogensen, M. Highly efficient high temperature electrolysis. J. Mater. ...