Gold is highly valued for its enduring luster; jewelry made from it remains tarnish-free for thousands of years. The reason behind this has long been a mystery to scientists
A new study, published in the journal Physical Review Letters and conducted by scientists from Tulane University in the United States, reveals the mechanism behind gold's ability to retain its luster and resist oxidation. The researchers used computer modeling of atoms and electrons to study the interaction of oxygen with the gold surface, discovering that surface atoms spontaneously rearrange themselves, forming protective structures that limit oxidation. The number of interactions with oxygen decreases by a factor of one billion to one trillion.
The researchers point out that without this atomic arrangement, oxygen molecules would have separated and reacted more easily with the gold. This nanoscale organization forms a protective barrier that preserves the metal's luster for extended periods.
According to the researchers, this discovery not only explains a well-known property of gold but may also contribute to the development of more efficient gold-based catalysts. These catalysts are already used in numerous industrial applications; for example, gold-palladium catalysts are used in the production of vinyl acetate, a key component in plastics manufacturing. Carbon monoxide removal from exhaust gases and propylene oxide production are among the most promising applications of these catalysts.
However, gold's stability and resistance to oxidation may limit its catalytic activity in some chemical processes and reactions. Therefore, researchers have previously resorted to combining it with other metals or using nanoparticles to enhance its properties. The new findings suggest a different approach based on controlling the surface structure and atomic arrangement, which could contribute to boosting gold's catalytic efficiency.
