4f-modified Ru-O polarity as a descriptor for efficient electrocatalytic acidic oxygen evolution

Xiuxiu Zhang, Yuhao Zhang, Bogdan O. Protsenko, Mikhail A. Soldatov, Jing Zhang, Chenyu Yang, Shuowen Bo, Huijuan Wang, Xin Chen, Chao Wang, Weiren Cheng, Qinghua Liu

Abstract: The development of non-iridium-based oxygen evolution reaction (OER) catalysts is crucial for proton exchange membrane water electrolysis (PEMWE), but hydrogen production remains a great challenge because of sluggish OER kinetics and severe catalyst dissolution. Here, we present a 4f-induced covalent polarity modulation strategy for the construction of 4f-orbital-modified RuO2 (4f-RuO2) nanocatalysts with tunable Ru–O polarity. We find that the OER activity of 4f-RuO2 shows a volcano shape as a function of the polarity of Ru–O bond. Consequently, the best 4f-Nd-RuO2 catalyst possesses an ultra-low overpotential of 214 mV at 10 mA cm−2 and robust electrochemical stability in 0.1 M HClO4. Theoretical calculations coupled with in situ synchrotron infrared and X-ray absorption spectroscopy analyses reveal that the modulation of Ru–O polarity in RuO2 by the valence f−p−d gradient orbital coupling can modify the adsorption energy of the reaction intermediates and suppress the participation of lattice oxygen to avoid over-oxidation of Ru, which can thus serve as an effective descriptor for fine tuning the activity and durability of acidic OER nanocatalysts. The sluggish oxygen evolution reaction kinetics and intense catalyst degradation under acidic conditions limit the practical application of electrolyzers. Here, the authors construct 4f-orbital-modified RuO2 catalysts with tunable Ru–O polarity that enhance catalytic activity and durability.

External IDs:doi:10.1038/s41467-025-62258-z