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

摘要

The design of active and durable catalysts for the Hsub2/subO/Osub2/sub interconversion is one of the major challenges of electrocatalysis for renewable energy. The oxygen evolution reaction (OER) is catalyzed by SrRuOsub3/sub with low potentials (ca. 1.35 VsubRHE/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 SrRuOsub3/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 RuOsub6/sub octahedra. These results illustrate how high OER activity and durability can be simultaneously engineered by chemical doping of perovskites.