Nanospectroscopy highlights
- Nanospectroscopy highlights
- Subfilamentary Networks in Memristive Devices
- Graphene and h-BN by a Single Molecular Precursor
- Fabrication of 2D heterojunction in graphene
- Island Ripening in a catalytic reaction
- Nanobubbles at GPa pressure under graphene
- Edge specific graphene nanoribbons
- Imaging the way molecules desorb from catalysts
- Towards the perfect graphene membrane
- Rippling of graphene on Ir(100)
- Thinnest loadstone ever
- Thermal stability of Graphene on Re(001)
- Stress Engineering at the Nanometer Scale
- Image blur in XPEEM
- AFM domain imaging using LEEM
- ARPES on corrugated graphene
- Corrugation in Exfoliated Graphene
- Domain-Wall Depinning by Spin Currents
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Island Ripening in a catalytic reaction
Island ripening is a fundamental process in physical chemistry in which small particles of a new phase grow in size in order to reduce interfacial energies. In the well- known Ostwald ripening, an evaporation-condensation mechanism causes large islands to grow at the expense of smaller ones. Here we report a new ripening mechanism based on a chemical reaction. This chemistry-based ripening process was seen during catalytic methanol oxidation on ultrathin vanadium oxide layers. We observe that under reaction conditions neighboring vanadium oxide islands move towards each other and coalesce. In order to elucidate the chemical and structural changes behind the island movement, microprobe XPS and microprobe LEED measurements were performed at Nanospectroscopy beamline at Elettra. The mechanism we propose here is based on an equilibrium, which is sensitive to gradients in the adsorbate coverages, between large |
VOx islands on Rh(111) and isolated small VnOm clusters. With such a polymerization-depolymerization mechanism, islands do not move as a whole, but are decomposed into small parts, i.e., clusters, that easily diffuse across the surface. Elucidating the mechanism of island ripening is essential for understanding the dynamic restructuring of supported oxide catalysts under operation conditions, and for designing catalysts with a desired morphology. Retrieve articleIsland Ripening via a Polymerization-Depolymerization Mechanism;M. Hesse, B. von Boehn, A. Locatelli, A. Sala, T.O. Menteş, and R. Imbihl; Phys. Rev. Lett. 115, 136102 (2015); doi: 10.1103/PhysRevLett.115.136102. |