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

• Published in: Nature materials 2019-07, Vol.18 (7), p.752-759
• Main Authors: Vøllestad, Einar, Strandbakke, Ragnar, Tarach, Mateusz, Catalán-Martínez, David, Fontaine, Marie-Laure, Beeaff, Dustin, Clark, Daniel R., Serra, Jose M., Norby, Truls
• Format: Article
• Language: English
• Subjects: 639/301/299/161; 639/301/299/886; 639/301/299/893; Anodes; Barium zirconates; Biomaterials; Chemistry and Materials Science; Condensed Matter Physics; Conduction; Electrode polarization; Electrolysis; Energy storage; Hydrogen; Hydrogen production; Materials Science; Modularity; Nanotechnology; Optical and Electronic Materials; Perovskites; Protons; Renewable energy sources; Steam; Water splitting
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/s41563-019-0388-2

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 BaZrO 3 -based tubular PCE, with 10 cm 2 active area and a hydrogen production rate above 15 Nml min −1 . The novel steam anode Ba 1− x Gd 0.8 La 0.2+ x Co 2 O 6− δ exhibits mixed p-type electronic and protonic conduction and low activation energy for water splitting, enabling total polarization resistances below 1 Ω cm 2 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. Proton ceramic electrolysers can produce hydrogen directly from steam, but their development has suffered from limited electrical efficiency. A fully operational and stable BaZrO 3 -based tubular electrolyser with high hydrogen production rate is now reported.