Nanoceria-Supported Ruthenium(0) Nanoparticles: Highly Active and Stable Catalysts for Hydrogen Evolution from Water

Ruthenium(0) nanoparticles supported on nanoceria (Ru 0 /CeO 2 ) were prepared by reduction of Ru 3+ ions on the surface of ceria using aqueous solution of NaBH 4 . The Ru 0 /CeO 2 samples were characterized by advanced analytical tools and employed as electrocatalysts on the glassy carbon electrode (GCE) in hydrogen evolution from water. The GCE, modified by Ru 0 /CeO 2 (1.86 wt % Ru), provides an incredible electrocatalytic activity with a high exchange current density of 0.67 mA·cm –2, low overpotential of 47 mV at j = 10 mA·cm –2, and small Tafel slope of 41 mV·dec –1 . Moreover, this modified GCE provides an unprecedented long-term stability without changing the onset potential (33 mV) even after 10 000 scans in acidic water splitting at room temperature. The hydrogen gas, evolved during the water splitting using the Ru 0 /CeO 2 (1.86 wt % Ru) electrocatalyst, was also collected. The amount of the evolved H 2 gas matches well with the calculated value, which indicates the achievement of nearly 100% Faradaic efficiency.