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

ABSTRACT: The design of active and durable catalysts for the H₂O/O₂ interconversion is one of the major challenges of electrocatalysis for renewable energy. The oxygen evolution reaction (OER) is catalyzed by SrRuO₃ 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 SrRuO₃ 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 RuO₆ octahedra. These results illustrate how high OER activity and durability can be simultaneously engineered by chemical doping of perovskites.

SUBMITTER: Retuerto M 

PROVIDER: S-EPMC6499887 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature