Synopsis: Training Catalytic Atoms to Stop Fidgeting

Single atoms deposited on an iron oxide surface provide a valuable model system for studying catalysis.
Synopsis figure
Courtesy of Z. Novotný and M. Schmid/Vienna University of Technology

Much of modern industrial chemistry relies on catalysts to drive useful reactions toward desired end products and increased yields. What makes these catalysts successful becomes clearer only with the ability to identify and analyze individual atoms on oxide surfaces, so having model systems to explore the chemistry and physics of surfaces is crucial. In a paper in Physical Review Letters, Zbynĕk Novotný and colleagues at the Vienna University of Technology, Austria, report their development of thermally stable arrays of gold atoms on iron oxide that may be ideal for answering key questions in catalysis.

Previous work has hinted at a size effect in catalysis: as clusters of catalytic metal atoms get smaller and smaller, they become more chemically active. Taken to the limit, individual atoms may be the most active, but studying this behavior demands a stable, well-characterized combination of atom and surface. Typically, however, gold atoms are highly mobile on these kinds of substrates and researchers have to cool them to cryogenic temperatures to hold them steady, making investigation under realistic conditions difficult.

Novotný et al. find that gold atoms sit comfortably on single crystals of Fe3O4 (magnetite) cut to present a particular surface structure at temperatures as high as 400C. Owing to charge ordering in the iron oxide, the surface acquires a lateral electronic structure that may stabilize the gold atoms, along with several other adsorbed atoms studied by the researchers. This suggests that the team has discovered a model system that may be universally applicable to detailed investigations of small cluster catalysis under actual reaction conditions. – David Voss


Announcements

More Announcements »

Subject Areas

NanophysicsChemical PhysicsMaterials Science

Previous Synopsis

Next Synopsis

Related Articles

Viewpoint: How to Fracture a Fluid
Fluid Dynamics

Viewpoint: How to Fracture a Fluid

High-speed imaging shows that fluids can break like brittle glass under the right conditions. Read More »

Synopsis: Rydberg Atom Takes a Dip in the Cold Sea
Atomic and Molecular Physics

Synopsis: Rydberg Atom Takes a Dip in the Cold Sea

A Rydberg atom immersed in a dense cloud of ultracold neutral atoms can undergo two chemical processes. Read More »

Synopsis: So Many Cracks, So Little Time
Fluid Dynamics

Synopsis: So Many Cracks, So Little Time

Water droplets impacting a cold surface exhibit a variety of fracture patterns depending on the temperature of the surface. Read More »

More Articles