Highly porous ruthenate pyrochlore with ultrasmall Ru nanoparticles and a P dopant for efficient oxygen evolution electrocatalysts in an alkaline medium

Abstract

To enhance green energy technologies, such as metal–air batteries, designing a highly efficient electrocatalyst for the oxygen evolution reaction is crucial because of its sluggish kinetics. In this study, pyrochlore oxide was uniquely synthesized with ultrasmall Ru nanoparticles, a highly porous structure, and a P dopant via simple in situ exsolution, resulting in an outstanding intrinsic activity and surface area. The porous structure of pure pyrochlore was optimized by controlling the temperature of the cross-linking process. The pyrochlore cross-linked at 80 ℃ (YRO-80) had the highest Brunauer-emmett-Teller (BET) surface area (186.1 m2/g). Ultrasmall Ru nanoparticles anchored on Y2R2O7 pyrochlore with the P dopant (Ru/YRO-P) were simply synthesized using a one-step process. The high electrocatalytic performance of Ru/YRO-P was demonstrated by its low overpotential (232 mA/cm2), low Tafel slope (41 mV/dec), and high power density (179.2 mW/cm2) in Zn–air battery applications. This paper presents a rational design strategy for enhanced electrocatalysts.