An FePb-doped RuO2 coupled amorphous/crystalline heterophase for efficient acidic oxygen evolution reaction

Abstract

The rational design of efficient ruthenium-based materials for the oxygen evolution reaction (OER) is promising for developing proton exchange membrane water electrolysis (PEMWE). Herein, an FePb-doped RuO₂ catalyst associated with an amorphous/crystalline heterostructure is presented for efficient acidic OER. Owing to the dual doped alien atoms and the heterophase, the synthesized FePb-RuO₂ exhibits a small overpotential of 194 mV at 10 mA cm⁻² in 0.5 M H₂SO₄. For application in PEMWE, the FePb-RuO₂ based electrolyser requires only 1.59 V to reach 500 mA cm⁻² and has stable operation for 100 h at 100 mA cm⁻². The abundant amorphous/crystalline heterostructure not only provides substantial defects and active sites but also inhibits the conversion of Ru⁴⁺ to unstable high valence states, improving OER activity and stability. Density functional theory simulation indicates that Fe dopants can weaken the adsorption strength of OOH* on Ru active sites, thereby enhancing OER activity. In contrast, Pb dopants can increase Ru reconstruction's activation energy, thus providing superior OER stability.