Selective Etching Induced Synthesis of Hollow Rh Nanospheres Electrocatalyst for Alcohol Oxidation Reactions

The hollow noble metal nanostructures have attracted wide attention in catalysis/electrocatalysis. Here a two‐step procedure for constructing hollow Rh nanospheres (Rh H‐NSs) with clean surface is described. By selectively removing the surfactant and Au core of Au‐core@Rh‐shell nanostructures (Au@Rh NSs), the surface‐cleaned Rh H‐NSs are obtained, which contain abundant porous channels and large specific surface area. The as‐prepared Rh H‐NSs exhibit enhanced inherent activity for the methanol oxidation reaction (MOR) compared to state‐of‐the‐art Pt nanoparticles in alkaline media. Further electrochemical experiments show that Rh H‐NSs also have high activity for the electrooxidation of formaldehyde and formate (intermediate species in the course of the MOR) in alkaline media. Unfortunately, Rh H‐NSs have low electrocatalytic activity for the ethanol and 1‐propanol oxidation reactions in alkaline media. All electrochemical results indicate that the order of electrocatalytic activity of Rh H‐NSs for alcohol oxidation reaction is methanol (C1) > ethanol (C2) > 1‐propanol (C3). This work highlights the synthesis route of Rh hollow nanostructures, and indicates the promising application of Rh nanostructures in alkaline direct methanol fuel cells. The hollow Rh nanospheres exhibit a more robust methanol electrooxidation property than Au@Rh core–shell nanostructures, and commercial Pt nanoparticles in alkaline media.