Dmitry Galyamin, Jorge Torrero, Isabel Rodríguez, Manuel J. Kolb, Pilar Ferrer, Laura Pascual, Mohamed Abdel Salam, Diego Gianolio, Verónica Celorrio, Mohamed Mokhtar, Daniel Garcia Sanchez, Aldo Saul Gago, Kaspar Andreas Friedrich, Miguel A. Peña, José Antonio Alonso, Federico Calle-Vallejo, María Retuerto & Sergio Rojas
Nature Communications volume 14, Article number: 2010 (2023)
Date: april-10. 2023.
The production of green hydrogen in water electrolyzers is limited by the oxygen evolution reaction (OER). State-of-the-art electrocatalysts are based on Ir. Ru electrocatalysts are a suitable alternative provided their performance is improved. Here we show that low-Ru-content pyrochlores (R2MnRuO7, R = Y, Tb and Dy) display high activity and durability for the OER in acidic media. Y2MnRuO7 is the most stable catalyst, displaying 1.5 V at 10 mA cm−2 for 40 h, or 5000 cycles up to 1.7 V. Computational and experimental results show that the high performance is owed to Ru sites embedded in RuMnOx surface layers. A water electrolyser with Y2MnRuO7 (with only 0.2 mgRu cm−2) reaches 1 A cm−2 at 1.75 V, remaining stable at 200 mA cm−2 for more than 24 h. These results encourage further investigation on Ru catalysts in which a partial replacement of Ru by inexpensive cations can enhance the OER performance.