Tiny gold clusters seen as good catalysts

Sept. 9, 2008 at 2:59 PM   |   Comments

GAITHERSBURG, Md., Sept. 9 (UPI) -- U.S.-led scientists say they have, for the first time, achieved state-of-the-art resolution of active gold nanocrystals absorbed onto iron oxide surfaces.

Using two scanning transmission electron microscopy instruments, the researchers said the resolution was sensitive enough to visualize individual gold atoms.

The scientists from the National Institute of Standards and Technology, Lehigh University and Cardiff University in Wales note gold has an exceptional ability to catalyze a wide variety of chemical reactions, including the oxidation of poisonous carbon monoxide into harmless carbon dioxide.

Previous studies suggested there's a critical size range at which gold nanocrystals become highly active as catalysts for CO oxidation. But that theory is based on research using idealized catalyst models made of gold absorbed on titanium oxide.

The new imaging technique allowed the researchers to study the real iron oxide catalyst systems as synthesized, identify all gold structures present in each sample and then characterize which cluster sizes are most active in CO conversion.

The study showed the most active gold nanoclusters for CO conversion are bilayers approximately 0.5-0.8 nanometers in diameter and containing about 10 gold atoms.

The study is reported in the Sept. 5 issue of the journal Science.

© 2008 United Press International, Inc. All Rights Reserved. Any reproduction, republication, redistribution and/or modification of any UPI content is expressly prohibited without UPI's prior written consent.
Recommended UPI Stories
Featured UPI Collection
Celebrity Couples of 2014 [PHOTOS]

Celebrity Couples of 2014 [PHOTOS]

Most Popular
Hurricane Katrina nine years later
Latvia boasts world's first net for migrating bats
Apple reportedly delays launch of rumored iWatch
New space debris monitoring facility set for Australia
Type Ia supernovas: the zombies of the cosmos
Trending News