No abstract

noble metal nanostructures have abundant active sites and are ideal catalysts for fuel cell reactions. However, it is still a huge challenge to realize the synthesis of precious metal nanosheets (NSs) with a clean surface. Here, we employed a square-wave potential electrodeposition method to synthesize a three-dimensional (3D) nanostructure composed of 2D maple leaf-like Rh NSs without introducing any surfactants and capping agents. The factors affecting the electrochemical growth of Rh nanoparticles (NPs) were carefully checked. Studies found that the balance between the growth and etching played the key role in the formation of a 3D nanostructure composed of 2D maple leaf-like Rh NSs. Due to the unique morphology and clean surface with a (111) facet, they exhibited excellent electrocatalytic activity and stability to the formic acid oxidation reaction. The peak current density of the maple leaf-like Rh NSs was 3.66 mA cm −2 , which was much higher than those of other Rh NPs prepared by electrodeposition. This work could provide a new idea to construct 3D nanocatalysts with a clean surface for fuel cells.

In the field of catalysis, the design and construction of nanomaterials is an efficient way to optimize the catalytic activity of catalysts. This study presents the synthesis of PtCu tripod...

The bimetallic nanoparticles of Pt-group metals surrounded by high-index facets have both alloying electronic effects and surface structure effects and are promising catalysts for fuel cells. In this work, the electrochemical square wave potential method was used to prepare Pt–Rh trioctahedral nanocrystals with {441} high-index facets without introducing any surfactants. The structures of the nanocrystals were checked carefully and the effects of parameters such as growth/etching potential, frequency, concentrations of precursors, etc., were also investigated systematically. The balance between etching and growth was found to be crucial in the successful synthesis of Pt–Rh trioctahedral nanocrystals. Due to the unique surface structure as well as alloy effect, the prepared Pt–Rh trioctahedral nanocrystals exhibited excellent electrocatalytic activities for methanol and ethanol oxidation reactions and were 5.3 times and 3.8 times more active than those of commercial Pt/C catalysts, respectively. In addition, the Pt–Rh trioctahedral nanocrystals as-synthesized showed stability much better than that of commercial Pt/C, which was critical for practical application.

Bi−component core−shell catalysts constructed from both noble and transition metals have been widely used in alcohol oxidation reactions, especially the introduction of transition metal components that can improve the anti−poisoning...