A Long‐Range Disordered RuO₂ Catalyst for Highly Efficient Acidic Oxygen Evolution Electrocatalysis

Abstract

Non-iridium acid-stabilized electrocatalysts for oxygen evolution reaction (OER) are crucial to reducing the cost of proton exchange membrane water electrolyzers (PEMWEs). Here, we report a strategy to modulate the stability of RuO₂ by doping boron (B) atoms, leading to the preparation of a RuO₂ catalyst with long-range disorder (LD-B/RuO₂). The structure of long-range disorder endowed LD-B/RuO₂ with a low overpotential of 175 mV and an ultra-long stability, which can maintain OER for about 1.6 months at 10 mA cm^-2 current density in 0.5 M H₂SO₄ with almost invariable performance. More importantly, a PEM electrolyzer using LD-B/RuO₂ as the anode demonstrated excellent performance, reaching 1000 mA cm^-2 at 1.63 V with durability exceeding 300 h at 250 mA cm^-2 current density. The introduction of B atoms induced the formation of a long-range disordered structure and symmetry-breaking B-Ru-O motifs, which enabled the catalyst structure to a certain toughness while simultaneously inducing the redistribution of electrons on the active center Ru, which jointly promoted and guaranteed the activity and long-term stability of LD-B/RuO₂. This study provides a strategy to prepare long-range disordered RuO₂ acidic OER catalysts with high stability using B-doping to perturb crystallinity, which opens potential possibilities for non-iridium-based PEMWE applications.