The Impact of Molecular Adsorption on the Quantized Electronic Structure of Oxide-Supported Nanoparticles

Gold nano-catalysis reminds me of the alchemists ’ search for the Philosopher’s stone as they tried to use it to transform base metals into noble ones. The irony of the story is that nowadays we try to use their unachieved goal (gold) as a tool to transform chemi-cal “waste ” materials such as carbon dioxide into chemically useful species such as carboxylates or oxalates. Electron quantization is a fundamental phenomenon that accompanies the transition from bulk metals to nanoclusters. The associated opening of an energy gap at the Fermi level crucially affects various properties of the nanos-tructures such as their electrical and optical behavior as well as their perfor-mance in catalytic reactions. Low-temperature scanning tunneling microscopy and spectroscopy has been employed to analyze the formation of quantum well states in two-dimensional gold nanostructures on Magnesium oxide ultrathin films, concentrating on the size regime between 50 and 300 atoms where th