National Science Foundation Goal: Development of new catalysts, anode and cathode materials is critical for advancing fuel cell technology. An alternative to noble metal catalysts are transition metal carbides such as tungsten or vanadium carbides. Challenge: In transition metal carbides the surface oxidation can disrupt performance. We proposed the use of carbon rich surfaces to replenish and reduce an oxidized surface and thus retain their activity. Results : • W-carbide thin films with controlled W/C ratio • Graphene or graphite termination is determined by carbon content • Carbide is epitaxial – cubic phase of carbide is stabilized by MgO interface even for 80 nm thin films • Systematic study of oxidation for carbon nanosphere, W-clusters and a wide range of carbide films. • Proof of surface recovery by annealing [see next slide] which was one of the Oxidation of Stoichiometric and Carbon-Rich Tungsten Carbide Surfaces Petra Reinke, University of Virginia Main Campus, DMR 1005809
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Goal: Development of new catalysts, anode and cathode materials is critical for advancing fuel cell technology. An alternative to noble metal catalysts are transition metal carbides such as tungsten or vanadium carbides.
Challenge: In transition metal carbides the surface oxidation can disrupt performance. We proposed the use of carbon rich surfaces to replenish and reduce an oxidized surface and thus retain their activity.
Results : • W-carbide thin films with controlled W/C ratio• Graphene or graphite termination is
determined by carbon content• Carbide is epitaxial – cubic phase of carbide is
stabilized by MgO interface even for 80 nm thin films
• Systematic study of oxidation for carbon nanosphere, W-clusters and a wide range of carbide films.
• Proof of surface recovery by annealing [see next slide] which was one of the central goals in our proposal.
Petra Reinke, Assoc. Professor in Materials Science and Engineering at the University of Virginia, leads this project, which uses surface science to understand the synthesis and reactivity of transition metal carbides.
Oxidation of Stoichiometric and Carbon-Rich Tungsten Carbide Surfaces
Petra Reinke, University of Virginia Main Campus, DMR 1005809
Spectroscopy Map at 0.61 V – within the oxide bandgap
Each pixel corresponds to one Scanning Tunneling spectrum as shown in graph
Oxidation: etching of surface graphite and mixed oxide surface with WO3
Recovery: Segregation of new graphite – degree of oxidation significantly less
Oxidation of Stoichiometric and Carbon-Rich Tungsten Carbide Surfaces
Petra Reinke, University of Virginia Main Campus, DMR 1005809
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Petra Reinke, University of Virginia Main Campus, DMR 1005809
The book “Inorganic Nanostructures” has been published by Wiley-VCH in May 2012. It is a textbook, which introduces the exciting materials science of nanoscale materials.
The book includes discussions on the quantum mechanical basis of confinement and dimensionality for a wide range of nanostructures..
The major part of this book describes synthesis, and focuses then on the link between structure and properties for a multitude of inorganic materials, such as nanowires, quantum dots, and carbon based nanomaterials.
