Novel Hybrid Electrocatalyst with Enhanced Performance in Alkaline Media: Hollow Au/Pd Core/Shell Nanostructures with a Raspberry Surface

In this paper, a hollow Au/Pd core/shell nanostructure with a raspberry surface was developed for methanol, ethanol, and formic acid oxidation in alkaline media. The results showed that it possessed better electrocatalyst performance than hollow Au nanospheres or Pd nanoparticles. The nanostructure was fabricated via a two-step method. Hollow Au nanospheres were first synthesized by a galvanic replacement reaction, and then they were coated with a layer of Pd grains. Several characterizations such as transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) were used to investigate the prepared nanostructures. The intensive studies of fuel cells encouraged us to examine the electrocatalytic properties of the prepared nanostructures, and that alkaline media could supply a more active environment than acidic electrolyte in previous reports inspired us to operate the experiments in alkaline media. According to the results, this hollow Au/Pd core/shell nanostructure with a raspberry surface possesses excellent electrocatalytic properties and can be further used in direct alcohol/formic acid fuel cells (DAFCs or DFAFCs), sensors, and catalysts.