Titania, zirconia and hafnia supported ruthenium(0) nanoparticles: Highly active hydrogen evolution catalysts

Designing a cost-effective catalyst with high activity and stability for hydrogen evolution reaction (2H⁺ + 2e^- → H₂) is a big challenge due to increasing demand for energy. Herein, we report the electrocatalytic activity of glassy carbon electrodes with group 4 metal oxides (TiO₂, ZrO₂, HfO₂) supported ruthenium(0) nanoparticles in hydrogen evolution reaction. Electrochemical activity of modified electrodes is investigated by recording linear sweep voltammograms in 0.5 M H₂SO₄ solution. The results of electrochemical measurements reveal that among the three electrodes the glassy carbon electrode with Ru⁰/TiO₂ (1.20% wt. Ru) exhibits the highest activity with a relatively small Tafel slope of 52 mV dec^-1, the highest exchange current density of 0.728 mA cm^-2, and the smallest overpotential of 41 mV at j = 10 mA cm^-2. Furthermore, it demonstrates superior stability in acidic solution with an unaltered onset potential for long term electrochemical measurement.