First synthesis of RuSn solid-solution alloy nanoparticles and their enhanced hydrogen evolution reaction activity.

Solid-solution alloys based on platinum group metals and p-block metals have attracted much attention due to their promising potential as materials with a continuously fine-tunable electronic structure. Here, we report on the first synthesis of novel solid-solution RuSn alloy nanoparticles (NPs) by electrochemical cyclic voltammetry sweeping of RuSn@SnO NPs. High-angle annular dark-field scanning transmission electron microscopy and energy-dispersive X-ray spectroscopy maps confirmed the random and homogeneous distribution of Ru and Sn elements in the alloy NPs.

Reverse Monte Carlo modeling for local structures of noble metal nanoparticles using high-energy XRD and EXAFS.

Reverse Monte Carlo (RMC) modeling based on the total structure factor () obtained from high-energy X-ray diffraction (HEXRD) and the () obtained from extended X-ray absorption fine structure (EXAFS) measurements was employed to determine the 3-dimensional (3D) atomic-scale structure of Pt, Pd, and Rh nanoparticles, with sizes less than 5 nm, synthesized by photoreduction. The total structure factor and Fourier-transformed PDF showed that the first nearest neighbor peak is in accordance with that obtained from conventional EXAFS analysis. RMC constructed 3D models were analyzed in terms of prime structural characteristics such as metal-to-metal bond lengths, first-shell coordination numbers and bond angle distributions.

Correlation between the electronic/local structure and CO-oxidation activity of Pd Ru alloy nanoparticles.

Pd Ru nanoparticles (NPs) were observed to display enhanced CO oxidation activity with the maximum performance obtained at the composition = 0.5. To unveil the origin of this superior CO oxidation activity, we investigated the local structure, valence state, and electronic properties of Pd Ru NPs using synchrotron-based X-ray techniques.

structural study of non-aqueous Li-air batteries using synchrotron-based X-ray diffraction.

Non-aqueous lithium-air batteries (LABs) attract attention as a candidate technology for next-generation energy storage devices. It is crucial to understand how the discharge product LiO is formed and decomposed by the electrochemical reactions to improve the cycle performance and decrease the charge voltage, which are the most important subjects for LAB development. Here, X-ray diffraction with high-brilliant X-rays in a transmission mode was used to observe the intensity and structural changes of crystalline LiO in an operating non-aqueous LAB in real time, and the Li-O electrochemical reaction involving LiO formation and decomposition was clearly demonstrated.