Single atoms as a catalyst: Surprising effects ensue

Using single atoms lowers the cost of catalysts. For years, the metal nanoparticles used in catalysts have been getting smaller and smaller. Now, a research team at TU Wien in Vienna, Austria have shown that everything is suddenly different when you arrive at the smallest possible size: a single atom. Metals such as gold or platinum are often used as catalysts. In the catalytic converters of vehicles, for example, platinum nanoparticles convert poisonous carbon monoxide into non-toxic CO₂. Because platinum and other catalytically active metals are expensive and rare, the nanoparticles involved have been made smaller and smaller over time. "Single-atom" catalysts are the logical end point of this downsizing: The metal is no longer present as particles, but as individual atoms that are anchored on the surface of a cheaper support material.