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

Ru/RuO2 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 degrees C, confirming that the repulsion between the particles is strong enough to stabilize them in aqueous solution. When the Ru/RuO2 nanoparticles were loaded on metal oxide supports (CeO2, TiO2 and Al2O3), the structure of Ru core and RuO2 shell remained unchanged on CeO2 support, whereas Ru core was preferred to be oxidized to RuO2 on TiO2 and Al2O3. The catalytic oxidations of ethanol were chosen to compare the catalytic properties of the Ru/RuO2 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.