Work

Facet-selective etching by pyridazine toward robust ruthenium-based oxygen evolution catalysts

Year: 2025

Type: article

Abstract: Stable oxygen evolution reaction (OER) catalyst alternatives to the precious IrO2 catalysts are of great importance to the next-generation proton-exchange membrane (PEM) electrolyzers. RuO2-based materials are promising candidates but suffer from low stability under highly anodic potentials. Here, we reported a facet-selective etching strategy to improve the stability of polycrystalline RuO2 without significantly affecting the activity. The selective etching was enabled by the specific chemisorption of pyridazine (pyd) with contingent N atoms onto the RuO2 surface. The pyd-RuO2 catalyst, after etching, exhibited a low overpotential 247 mV at 100 mA·cm−2 and obvious stability improvement of over 200 h at 100 mA·cm−2 with only 0.63% Ru loss in acidic conditions. Combining various characterization techniques and theoretical calculations, we revealed that the crystalline RuO2 (110) facet is favorably etched by the coordination of pyridazine while protecting other surfaces, which significantly enriches the RuO2 (110) facets toward higher OER stability via the dynamic dissolution and repair mechanism in the ordered manner. This study offers alternative perspectives on the dissolution and stability mechanism of RuO2 and the facet-selective modulation of nanocrystals by ligand-driven etching.

Source: Nano Research

DOI: 10.26599/nr.2025.94907315