Mixed proton and electron conducting double perovskite anodes for stable and efficient tubular proton ceramic electrolysers


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 cm2 active area and a hydrogen production rate above 15 Nml min−1. The novel steam anode Ba1−xGd0.8La0.2+xCo2O6−δ exhibits mixed p-type electronic and protonic conduction and low activation energy for water splitting, enabling total polarization resistances below 1 Ω cm2 at 600 °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.

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Fig. 1: Schematics of water electrolysis technologies and PCE membrane and transport.
Fig. 2: Phase segregation and microscopy of BGLC.
Fig. 3: PCE electrochemical performance and literature comparison.
Fig. 4: PCE cell performance and characterization.
Fig. 5: Technological viability of tubular PCEs.
Fig. 6: Charge transfer and CFD models of PCE system.

Data availability

The data that support the findings of this study are available from the corresponding author upon reasonable request.


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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.

Author information

E.V., R.S., M.-L.F., J.M.S. and T.N. conceived, designed and supervised the research. D.B. prepared the tubular half cells. M.-L.F. prepared electrodes. E.V. and R.S. developed and synthesized electrode materials, fabricated the electrolysers from tubular half cells and electrode materials and conducted electrochemical characterization. E.V. made the electrochemical model. M.T. conducted stability tests and humidity measurements. D.R.C. performed the TEM work and graphical processing. D.C. and J.M.S. carried out the CFD calculations. All authors contributed to writing the manuscript.

Correspondence to Truls Norby.

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Supplementary Information

Supplementary Notes, Supplementary Figs. 1–15, Supplementary Tables 1–4, Supplementary references 1–14

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