Na-doped ruthenium perovskite electrocatalysts with improved oxygen evolution activity and durability in acidic media

• Published in: Nature communications Vol. 10; no. 1; p. 2041
• Main Authors: Retuerto, María, Pascual, Laura, Calle-Vallejo, Federico, Ferrer, Pilar, Gianolio, Diego, Pereira, Amaru González, García, Álvaro, Torrero, Jorge, Fernández-Díaz, María Teresa, Bencok, Peter, Peña, Miguel A., Fierro, José Luis G., Rojas, Sergio
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.05.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 140/146; 147/143; 639/301/299/161/886; 639/4077/909; 639/638/263/915; Adsorbates; Bonding strength; Catalysis; Catalysts; Doping; Durability; Electrocatalysts; Humanities and Social Sciences; Intermediates; multidisciplinary; Organic chemistry; Oxidation; Oxygen; Oxygen evolution reactions; Perovskites; Renewable energy; Ruthenium; Science; Science (multidisciplinary); Surface energy; Surface properties; Valence
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-09791-w

The design of active and durable catalysts for the H 2 O/O 2 interconversion is one of the major challenges of electrocatalysis for renewable energy. The oxygen evolution reaction (OER) is catalyzed by SrRuO 3 with low potentials (ca. 1.35 V RHE ), but the catalyst’s durability is insufficient. Here we show that Na doping enhances both activity and durability in acid media. DFT reveals that whereas SrRuO 3 binds reaction intermediates too strongly, Na doping of ~0.125 leads to nearly optimal OER activity. Na doping increases the oxidation state of Ru, thereby displacing positively O p-band and Ru d-band centers, weakening Ru-adsorbate bonds. The enhanced durability of Na-doped perovskites is concomitant with the stabilization of Ru centers with slightly higher oxidation states, higher dissolution potentials, lower surface energy and less distorted RuO 6 octahedra. These results illustrate how high OER activity and durability can be simultaneously engineered by chemical doping of perovskites. While water splitting may afford a renewable means to store energy in chemical bonds, water oxidation catalysts suffer from poor stabilities in acidic media. Here, authors show sodium doping of strontium ruthenate to improve the catalytic durability while maintaining a high O 2 evolution activity.