Dynamic self-healing in high-entropy oxide bi-functional catalyst drives stable PEMWE at ampere-level current density

Ruthenium exhibits catalytic activity comparable to that of iridium and platinum, yet at a substantially lower cost. However, its practical application is hindered by poor stability under acidic electrolyte conditions. Herein, we report a dynamic self-healing mechanism mediated by sustainable electron compensation in a LaRuCoMnVO x high-entropy oxide, which leads to a remarkable enhancement in catalytic durability. Furthermore, by optimizing the local electronic coordination environment, this strategy promotes the evolution of single active sites into dual active sites and reduces the adsorption energy. Benefiting from these synergistic effects, the catalyst demonstrates outstanding acidic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance, with overpotentials as low as 175 and 41 mV (at 10 mA cm -2 ), respectively. When integrated into a proton exchange membrane water electrolyzer (PEMWE), the system requires only 1.65 V to achieve a high current density of 1 A cm -2 and exhibits a minimal degradation rate of 12.9 μV h -1 . Both experimental and computational analyses confirm that sustainable electron donation to the Ru sites underpins the dynamic stability of the catalyst at ampere-level current densities. This electron compensation-driven self-healing strategy effectively eliminates the reliance on iridium and platinum, while simultaneously enhancing both activity and stability. Download: Download high-res image (472KB) Download: Download full-size image