The first example of the crystal structure control of Os is reported. The fcc-structured Os nanoparticles were synthesized using an Os acetylacetonate complex as a precursor although the fcc structure does not exist in the bulk state.

Transition metal carbides have attractive physical and chemical properties that are much different from their parent metals. Particularly, noble metal carbides are expected to be promising materials for a variety of applications, particularly as efficient catalysts. However, noble metal carbides have rarely been obtained because carbide phases do not appear in noble metal−carbon phase diagrams and a reasonable synthesis method to make noble metal carbides has not yet been established. Here, we propose a new synthesis method for noble metal carbides and describe the first synthesis of rhodium carbide using tetracyanoethylene (TCNE). The rhodium carbide was synthesized without extreme conditions, such as the very high temperature and/or pressure typically required in conventional carbide syntheses. Moreover, we investigated the electronic structure and catalytic activity for the hydrogen evolution reaction (HER). We found that rhodium carbide has much higher catalytic activity for HER than pure Rh. Our study provides a feasible strategy to create new metal carbides to help advance the field of materials science.

Unravelling kinetic oscillations, that arise spontaneously during catalysis, has been a challenge for decades; not only to understand these complex phenomena but also in an aim to exploit kinetics at the peak maxima. In this study, through temporally and spatially resolved operando analysis, we demonstrate that CO oxidation over Rh/Al2O¬3 involves a series of thermal levering events – CO oxidation, Boudouard reaction, and carbon combustion – which drive oscillatory CO2 formation. This catalytic sequence relies on harnessing localised temperature episodes at the nanoparticle level that provides an efficient means to drive unfavourable reactions, where the macroscopic conditions do not allow. This insight provides a new basis for coupling thermal events at the nanoscale for efficient harvesting of energy, essential for emerging net-zero carbon technologies.

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