Adsorbate-driven Morphological Changes Of A Gold Surface At Lowtemperatures

摘要

The notion of active site in heterogeneous catalysis as a static configuration of low-coordination surface atoms is being replaced by the concept of dynamic active site. This idea is directly supported by a growing number of experimental and theoretical results. For example, gold surfaces are undergoing significant restructuring in the presence of reactants or even weakly adsorbed molecules. Current interest in the reactivity of gold has its origin in discoveries of gold catalytic properties two decades ago. The unprecedented catalytic activity of supported Au nanoparticles in the low temperature CO oxidation stands in sharp contrast to the limited reactivity of the close-packed (111) surface of this noble metal. Present understanding is that CO adsorption requires the presence of low-coordination sites provided by stepped or more open surfaces of gold.