| May 21, 2026 |
Study finds gold atoms on common surfaces rearrange into protective patterns, suppressing oxygen reactions by a billion to a trillion times.
(Nanowerk News) Gold has been prized for thousands of years for its enduring shine, but Tulane University researchers have discovered that gold’s resistance to tarnishing depends on more than its chemistry.
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In a new study published in Physical Review Letters (“Role of reconstruction in the inertness of gold towards oxygen”), researchers found that atoms on certain gold surfaces naturally rearrange themselves into protective patterns that dramatically suppress reactions with oxygen.
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The discovery helps explain why gold jewelry and other gold objects can remain untarnished for centuries — and could also point the way toward designing more effective gold-based catalysts for industrial and energy-related applications.
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“People have generally thought gold doesn’t tarnish simply because it doesn’t interact strongly with oxygen,” said Matthew Montemore, associate professor in Chemical Engineering in Tulane’s School of Science and Engineering. “What we show is that for two of the most common gold surface types, the surface atoms actually rearrange themselves in a way that makes the gold much more resistant to oxidation.”
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Using computer simulations that predict how atoms and electrons behave, Montemore and co-author Santu Biswas, postdoctoral fellow in Tulane’s Department of Chemical & Biomolecular Engineering, studied how oxygen molecules interact with two common gold surface structures. They found that without this atomic rearrangement, oxygen molecules could break apart and react with gold much more easily.
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Instead, the rearranged surfaces suppress oxygen reactions by a factor of a billion to a trillion, essentially creating a protective atomic-scale barrier that helps gold stay shiny indefinitely.
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The findings offer a new explanation for one of gold’s best-known properties while also opening the door to potential advances in catalysis.
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Gold-based catalysts — materials that help speed chemical reactions — are already used in some industrial oxidation reactions. But gold’s natural resistance to breaking apart oxygen molecules, the same trait that makes it attractive for jewelry and electronics, can also limit its usefulness in chemical manufacturing and energy applications.
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Gold-palladium catalysts are used to make vinyl acetate, a chemical building block for many plastics and other materials. Researchers are also studying gold catalysts for uses such as cleaning up carbon monoxide in car exhaust and making propylene oxide, an important industrial chemical.
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“If you can trick gold into dissociating oxygen, it can actually become a very effective catalyst for certain reactions,” Montemore said. “Our work suggests a new strategy for potentially doing that by preventing or reversing these surface rearrangements.”
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Researchers have traditionally tried to improve gold catalysts by combining gold with other metals or using tiny gold nanoparticles on oxide surfaces. The new findings suggest surface geometry itself may provide another route to enhancing gold’s catalytic activity.
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