Multi-Component and Nanoporous Design toward RuO₂-Based Electrocatalyst with Enhanced Performance for Acidic Water Splitting

Developing electrocatalysts with excellent activity and stability for water splitting in acidic media remains a formidable challenge due to the sluggish kinetics and severe dissolution. As a solution, a multi-component doped RuO₂ prepared through a process of dealloying-annealing is presented. The resulting multi-doped RuO₂ possesses a nanoporous structure, ensuring a high utilization efficiency of Ru. Furthermore, the dopants can regulate the electronic structure, causing electron aggregation around unsaturated Ru sites, which mitigates Ru dissolution and significantly enhances the catalytic stability/activity. The representative catalyst (FeCoNiCrTi-RuO₂) shows an overpotential of 167 mV at 10 mA cm⁻² for oxygen evolution reaction (OER) in 0.5 m H₂SO₄ solution with a Tafel slope of 53.1 mV dec⁻¹, which is among the highest performance reported. Moreover, it remains stable for over 200 h at a current density of 10 mA cm⁻². This work presents a promising approach for improving RuO₂-based electrocatalysts, offering a crucial advancement for electrochemical water splitting.