Optimizing Stability and Efficiency in Low-Content Noble Metal-Doped Aerogel Catalysts for Oxygen Evolution Reaction

This study presents the development of an efficient Oxygen Evolution Reaction (OER) electrocatalyst by doping low-content Ruthenium (Ru) into Fe_xCo_5-x (oxy)hydroxide aerogel matrix. The aerogel, synthesized using a sol-gel process and supercritical drying, ensures uniform dispersion of Ru within the porous structure, significantly regulating the catalytic performance and stability of the OER electrocatalyst. The incorporation of Ru not only enriches the active sites but also generates synergistic effects with existing active sites, further improving the overall catalytic efficiency. The optimized catalyst with low Ru content delivers outstanding performance metrics, e.g., 1%Ru-Fe₄Co₁ catalyst demonstrates outstanding OER performance, with an onset overpotential (η_onset) of 177.4 mV, η₁₀ of 214.3 mV, η₁₀₀ of 335.9 mV, a Tafel slope of 41 mV dec⁻¹, and remarkable Mass Activity of 569.1 A/g_metal at 1.63 V (vs. RHE). It also exhibits good stability under operational conditions, maintaining performance at temperatures up to 60 °C and enduring high current densities up to 250 mA cm^{- 2}. Density Functional Theory (DFT) simulation elucidates the optimal doping level and uniform distribution enhance the reaction kinetics, leading to superior catalytic performance. This research provides new insights into the design of cost-effective, high-performance OER electrocatalysts by modulating low-content noble metals in aerogels.