Scientists' gold discovery sheds light on catalysis

Scientists' gold discovery sheds light on catalysis

(Phys.org) -- A physicist at the University of York has played a key role in international research which has made an important advance in establishing the catalytic properties of gold at a nano level.

Dr Keith McKenna was part of a research team which discovered that the catalytic activity of nanoporous gold (NPG) originates from high concentrations of surface defects present within its complex three-dimensional structure.

The research, which is published online in , has the potential to assist in the development of more efficient and durable and fuel cells because nanoporous gold is a catalytic agent for oxidising .

Bulk gold – the sort used in watches and jewellery – is inert but nanoporous gold possesses high catalytic activity towards oxidation reactions. The research team, which also included scientists from Japan, China and the USA, discovered, that this activity can be identified with surface defects found within its complex nanoporous structure. While nanoporous gold exhibits comparable activity to nanoparticulate gold, it is considerably more stable making it attractive for the development of catalysts with high performance and long lifetimes.

They created NPG by immersing an alloy of gold and silver in a chemical solution which removed the latter metal to create a porous atomic structure. Then, using transmission electron microscopy, they were able to detect evidence that the surface defects on the NPG were active sites for catalysis and the residual silver made them substantially more stable.

Dr McKenna, of the Department of Physics at the University of York, said: “Unlike gold nanoparticles, dealloyed NPG is unsupported so we are able to monitor its catalytic activity more accurately. We found that there are many surface defects present within the complex structure of NPG which are responsible for the high .

“This work has given us a greater understanding of the catalytic mechanisms of NPG which will, in turn, shed light on the mechanisms of gold catalysis more broadly.”


Explore further

To make better fuel cells, study the defects

More information: The paper ‘Atomic origins of the high catalytic activity of nanoporous gold’ is published online in Nature Materials.
Journal information: Nature Materials

Provided by University of York
Citation: Scientists' gold discovery sheds light on catalysis (2012, August 13) retrieved 26 August 2019 from https://phys.org/news/2012-08-scientists-gold-discovery-catalysis.html
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Aug 13, 2012
its the geometry not the material, how about finding cheaper stuff that has the same geometry and see if it works just as well.

FMA
Aug 13, 2012
NPG should be red-brown in colour not "gold" in colour.

Aug 13, 2012
how about finding cheaper stuff that has the same geometry and see if it works just as well.


I'd have thought they'd be able to reuse the silver ions.

Aug 13, 2012
This was a benchtop prep, not a production run. They probably did not have enough silver involved to make its recovery economically feasible, although that may change soon the way the price is climbing.
An alternate method for preparing NPG might be electroless plating of gold (or nickel or whatever transition metal catalyst one is interested in) within a spatial matrix such as an aerogel.

Aug 13, 2012
I only looked at the picture and thought this was some sort of marvelous CHEESE DISCOVERY.

Now I'm disappointed and hungry.

Aug 13, 2012
I only looked at the picture and thought this was some sort of marvelous CHEESE DISCOVERY.

Now I'm disappointed and hungry.


What a cheesy remark...

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