Anchoring ruthenium nanoclusters using an electron-donating fullerene carbon matrix for high-performance hydrogen evolution

The development of highly efficient and stable electrocatalysts for the hydrogen evolution reaction (HER) is essential for sustainable hydrogen production through water electrolysis. Herein, we report a superior HER electrocatalyst, Ru/FCF-600, fabricated by anchoring ruthenium nanoclusters onto a defect-rich fullerene carbon framework (FCF). The FCF support was synthesized using Santa Barbara Amorphous-15 (SBA-15) as the template and fullerene (C₆₀) as the precursor, followed by high-temperature calcination and hydrofluoric acid etching. Comprehensive characterization techniques reveal that an annealing temperature of 600 °C is optimal for forming highly crystalline and uniformly dispersed Ru nanoparticles. The electron transfer from the defective carbon support to the Ru nanoclusters results in an electron-enriched Ru state. This electronic modulation endows the Ru/FCF-600 catalyst with exceptional HER activity in 1.0 M KOH, requiring an ultralow overpotential of only 23 mV to achieve 10 mA cm^-2, outperforming commercial Pt/C and Ru/C benchmarks. The catalyst also exhibits a small Tafel slope of 37.80 mV dec^-1, a high turnover frequency (21.42 s^-1 at 100 mV), and nearly 100% Faradaic efficiency. Furthermore, it demonstrates outstanding long-term stability for over 80 hours. When coupled with an IrO₂ anode for overall water splitting, the Ru/FCF-600∥IrO₂ system requires a low cell voltage of 1.49 V at 10 mA cm^-2 and operates stably for 100 hours at 100 mA cm^-2. More importantly, the anion-exchange membrane water electrolyzer (AEMWE) assembled with Ru/FCF-600 as the cathode achieves a high current density of 1 A cm^-2 at a low cell voltage of 1.65 V. This work underscores the pivotal role of electronic metal-support interaction (EMSI) in designing and optimizing high-performance HER electrocatalysts.