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Electroreduction of carbon dioxide (CO2RR) into fuels and chemicals is an appealing approach to tackle CO2 emission challenges.

Constructing core–shell nanostructures is demonstrated to be an effective strategy to improve catalytic activity of metal nanoparticles. However, the impact of the atomic ordering of the metal core on the performance of the shell remains unexplored. Here, ruthenium–platinum (Ru–Pt) core–shell nanoparticles, with a crystalline and amorphous Ru core of the same diameter and diverse Pt shell thicknesses, are prepared and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-angle annular dark-field scanning transition electron spectroscopy (HAADF-STEM), and CO tripping voltammetry. The well-defined heterostructured Ru–Pt interface and anisotropic growth of the Pt shell on the crystalline Ru core (Ru@Pt x ) were observed, while the amorphous Ru core induces a partial alloy at the Ru–Pt interface and isotropic growth of the Pt shell. The core–shell structure also results in an apparent down-shift of the d-band center of Pt, which dissipates much faster on the amorphous Ru core than on crystalline ones, as demonstrated by the XRD and CO desorption potential. The two sets of core–shell nanoparticles show that a volcano-shape dependence of the catalytic activity on the thickness of the Pt shell and the crystalline Ru core markedly enhanced the catalytic performance and stability toward electro-oxidation of formic acid and ethanol, which is ascribed to the lattice strain of the Pt shell, down-shift of the d-band center, the weakened CO adsorption, and thus alleviated poisoning.

The slow kinetics of oxygen evolution reaction (OER) has seriously hindered the development of electrical water splitting and rechargeable metal-air batteries. The ethanol oxidation reaction (EOR) to replace OER is...

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Development of low-cost and high-efficiency electrocatalysts for hydrogen evolution reaction is a critical step toward sustainable water splitting. Herein, in situ growth of heterostructured MoC/Mo2C nanoribbons and nanoflowers on copper foam (Mo x C/Cu), copper foil, and nickel foam (Mo x C/Ni) are prepared via a two-step method: hydrothermal preparation of molybdenum precursors followed by pyrolysis at controlled temperatures. The Mo x C/Cu hybrids are found to exhibit an excellent catalytic activity, as compared to the Mo x C/Ni and Cu foil counterparts, and the sample prepared at 750 °C stands out as the best among the series with a low overpotential of 169 mV to reach the current density of 200 mA cm–2 in 1 M KOH, and 194 mV in 0.5 M H2SO4, and the corresponding Tafel slopes of 98 and 74 mV dec–1, respectively. The electrocatalytic activity is also found to vary with the Mo2+/Mo3+ and N contents in the samples that impact the electrical conductivity and electron-transfer kinetics of the hydrogen evolution reaction. Results suggest that MoC/Mo2C heterostructured materials supported on copper foam may be a viable candidate to catalyze hydrogen evolution reaction in a wide range of pH.

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