The development of catalysts with high efficiency and stability in acidic electrolytes for oxygen evolution reaction (OER) is critical to water electrolyzers and renewable energy conversion and has been eagerly explored in the shape-controlled synthesis of noble metals such as Ir and Ru. However, the expensive prices of Ir and Ru severely hamper their wide use in OER. In this work, we show an efficient method for the one-pot synthesis of Ir0.4Cu0.6 microspheres. Electrochemical tests showed that the Ir–Cu microspheres as-synthesized delivered a prominent electrocatalytic activity toward OER in an acidic electrolyte with low overpotential (255 mV at 10 mA cm–2) and a small Tafel slope of 53.3 mV decade–1. They were much better than those of commercial Ir/C (331 mV at 10 mA cm–2 and Tafel slope of 100 mV decade–1). Moreover, the Ir0.4Cu0.6 as-synthesized also exhibited good stability for OER under acidic conditions, that is, after 30,000 s, the change of its potential was quite small in the chronopotentiometry test. The high catalytic performance could originate from the synergistic electronic interaction between iridium and copper atoms, which could modify the d-band center of iridium.

Without introducing any surfactants and capping agents, concave Pt nanocubes, willow-like Pt nanocrystals, and spherical Pt nanoparticles were synthesized at different deposition potentials using a square-wave potential electrodeposition procedure. As the deposition potentials decreased from the double layer region to the hydrogen underpotential deposition region and finally into the hydrogen evolution reaction region under acidic conditions, the morphology of Pt nanocrystals changed from spherical Pt nanoparticles to willow-like Pt nanocrystals and finally to concave Pt nanocubes. We took advantage of the unique features of hydrogen adsorption/desorption on the surface of Pt in different potential regions to achieve the shape-controlled synthesis of Pt nanocrystals, and the different degrees of interaction between hydrogen and Pt played a key role in obtaining nanocrystals with various shapes. Concave Pt nanocubes exhibited excellent electrocatalytic activity to the ethanol oxidation reaction, as compared to commercial Pt/C catalysts. The peak current density in the positive scan of concave Pt nanocubes was 2.3 mA cm–2, which was 4.7 times higher than that of commercial Pt/C.

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...

No abstract