Gold is not alone, he only has guards who protect him

To confirm this, the researchers studied how the oxygen molecule moves around each type of gold. He asked how many oxygen molecules could stick to the surface, and the molecules that stuck, what energy was needed for the oxygen molecule to split. He showed that the surface pattern often seen in bulk gold—the hexagonal pattern—doesn’t hold the solid air, and the air pattern is not deformed. This means that it still takes more energy to split an oxygen molecule into two atoms that are ready to react.

On the other hand, if the shape of the gold is a square shape, the oxygen molecules stick to the surface and deform to the point of splitting, leaving them to react (in fact, under these conditions, the gold will oxidize). The researchers estimate that gold’s square lattice behaves like conventional metals, such as platinum.

Hiding your small details

Gold surfaces are also active in the sense that the gold atoms can arrange themselves on the surface. When moving around, they change the visible layer to an inactive triangle. But the change, called surface reform, cannot be done in any way. Instead, the atoms move to form a repeating 2D pattern that covers the exposed face, and the space required to form a complete part of the structure is larger. At the density of gold, this is not an issue because there are so many atoms to go around, that each part can almost completely penetrate.

For nanoparticles, the story is different. Too many atoms means there aren’t enough atoms or surfaces to rebuild. So something that is known for its instability shows its true colors and starts to react and act as a catalyst.

These studies show how complex the details of chemistry and catalysis can be. Inert metals become active and then return to inertness due to changes in mass. It also opens up new avenues for research on catalysis, although I don’t think gold will be the catalyst of choice any time soon.

Physical Review Letters2026, PA: 10.1103/g3bc-t1qv