Gold's ability to catalyze the conversion of toxic carbon monoxide (CO) into more benign carbon dioxide (CO2) at room temperature lay hidden until the 1980s. Since the discovery, scientists have sought to determine exactly how gold nanoparticles function as catalysts. Now researchers from Lehigh University, Cardiff University, and the National Institute of Standards and Technology report that bilayer clusters measuring about one-half nanometer in diameter and containing about 10 gold atoms are responsible for triggering the CO oxidation reaction.
Using aberration-corrected transmission electron microscopy capable of resolving single gold atoms, they found that the drying of the catalyst in flowing rather than static air helps impart to the gold its catalytic capability. The gold catalysts could find a potential application in the protective masks capable of converting CO to CO2 that are worn by firefighters and others exposed to high levels of CO. Another application is fuel cells, which are vulnerable to poisoning by the CO that is present in the hydrogen fuel stream.
