Na-doped ruthenium perovskite electrocatalysts with improved oxygen evolution activity and durability in acidic media.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31053713.
- Also identified by DOI 10.1038/s41467-019-09791-w and PMC identifier 6499887.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The design of active and durable catalysts for the H<sub>2</sub>O/O<sub>2</sub> interconversion is one of the major challenges of electrocatalysis for renewable energy. The oxygen evolution reaction (OER) is catalyzed by SrRuO<sub>3</sub> with low potentials (ca. 1.35 V<sub>RHE</sub>), 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<sub>3</sub> 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<sub>6</sub> octahedra. These results illustrate how high OER activity and durability can be simultaneously engineered by chemical doping of perovskites.