Heterojunction-doping synergy in strontium palladium-ruthenium oxide catalysts for efficient oxygen evolution
Zixin Yan, Junjie Gong, Huali Sun, Tianchen Jin, Dian Yang, Lin Gu, Lili Zhang, Shijie Shen, Wenwu Zhong
Abstract
The industrial implementation of water electrolysis for hydrogen production is significantly hindered by the sluggish kinetics of the oxygen evolution reaction, while the high cost of state-of-the-art iridium-based catalysts remains a critical challenge. This work demonstrates an innovative heterojunction-doping synergy strategy through rational design of SrPd<sub>3-<em>x</em></sub>Ru<em><sub>x</sub></em>O<sub>4</sub>/SrRuO<sub>3</sub> composite electrocatalysts. The strategy combines the structural advantages of cubic-phase SrPd<sub>3</sub>O<sub>4</sub> and perovskite-type SrRuO<sub>3</sub>, where their inherent compatibility facilitates atomic-level interface formation through oxygen-bridge coordination. Simultaneously, controlled Ru substitution in the SrPd<sub>3</sub>O<sub>4</sub> lattice induces beneficial structural strain and precisely modulates the electronic environment to optimize intermediate adsorption energetics. The optimized catalyst exhibits exceptional electrocatalytic performance in 1 M KOH, delivering an overpotential as low as 227.6 mV at 10 mA cm<sup>-2</sup> and notably retaining stability for 300 hours at 50 mA cm<sup>-2</sup>. In situ Raman spectroscopy confirms the dominance of the adsorbate evolution mechanism, while theoretical calculations reveal that the synergistic effects diminish the activation energy barrier governing the rate-determining step. This work not only provides fundamental insights into the design of Pd-based oxide catalysts but also establishes a generalizable approach for developing high-performance electrocatalysts through synergistic structural engineering.