Electrochemical Synthesis of Catalytically Active Ru/RuO₂ Core−Shell Nanoparticles without Stabilizer

Ru/RuO 2 core−shell nanoparticles were synthesized by electrochemical method in water without the addition of stabilizers. The zeta potential of the fresh nanoparticles was 30.8 mV in pure water at 25 °C, confirming that the repulsion between the particles is strong enough to stabilize them in aqueous solution. When the Ru/RuO 2 nanoparticles were loaded on metal oxide supports (CeO 2, TiO 2 and Al 2 O 3 ), the structure of Ru core and RuO 2 shell remained unchanged on CeO 2 support, whereas Ru core was preferred to be oxidized to RuO 2 on TiO 2 and Al 2 O 3 . The catalytic oxidations of ethanol were chosen to compare the catalytic properties of the Ru/RuO 2 nanoparticles supported catalysts (our method) with that of Ru catalysts prepared by traditional wet impregnation method. All catalysts prepared by our method showed higher catalytic activities for the catalytic oxidations of ethanol than the Ru catalysts prepared by wet impregnation.