Hollow Au_xAg/Au core/shell nanospheres as efficient catalysts for electrooxidation of liquid fuels

Abstract

One plausible approach to endow nanocrystals with both enhanced catalytic activity and stability for the electrooxidation of liquid fuels is to chemically control the crystal structures of nanoparticles. To date, core-shell and alloy structures have been demonstrated to offer generally two precious opportunities to design highly efficient nanocatalysts for the electrooxidation reaction of organic molecules. We herein combine these two advantages and develop a general method to successfully synthesize hollow Au_xAg/Au core/shell nanospheres with a high yield approaching 100% via a combined seed mediated and galvanic replacement method. The results from the electrochemical measurements have revealed that this as-obtained hollow Au_xAg/Au core/shell nanosphere exhibited considerably high electrocatalytic performance towards ethylene glycol and glycerol oxidation with mass activity of 4585 and 3486 mA mg_Au^-1, which were 5.3- and 5.8-fold higher than that of pure Au. We trust this strategy may be extended to the syntheses of other multimetallic nanocatalysts with such fascinating nanostructures and the as-obtained hollow Au_xAg/Au core/shell nanospheres can be well applied to serve as highly desirable anode catalysts for the electrooxidation of ethylene glycol and glycerol.