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| Source: Bloomberg |
LAST week’s violent and fatal strike at Lonmin’s mine sent the
price of platinum skyrocketing to $1 473,10 an ounce at one stage.
For the manufacturers who are trying to build catalytic converters
that can scrub out the carcinogenic nitric oxide and nitrogen dioxide from
diesel fumes cheaply, this was very bad news. Which is why most of them will be
paying very close attention to the August 17 issue of Science, in
which Nanostellar in Redwood, California, reports that its computer models show
it can grow the mineral mullite as a cost-effective substitute for
platinum.
Mullite is a silicate mineral that was discovered on the Isle of
Mull in Scotland in 1924. As a mineral catalyst it outperforms platinum to
ensure clean exhaust gasses, but as it is so rare in nature, the exhaust-
manufacturing industry has not built any exhausts with it.
Instead, it has paid billions of rands into South Africa’s platinum
mines from Mpumalanga to the North West.
The news from Nanostellar that it has developed a synthetic form of
mullite at a fraction of the cost of platinum will ring very large alarm bells
in mining towns such as Rustenburg and Machadodorp, which are set to become
ghost towns like Welkom should Nanostellar manage to get its product to the
market.
Nanostellar develops advanced catalysts for an array of
applications that include emissions control, energy efficiency and the synthesis
of chemicals and fuels.
The company is located in Silicon Valley, California, and is funded
by venture capital and other private investors. It was founded in 2004 by
scientists from Stanford University and the Nasa Ames Research Centre.
A synthetic version of mullite is already produced commercially for
use in various porcelains, such as crucibles and heating balls. Mullite has a
very high melting point of 1 8400C, and as a
mixed-phase oxide mineral it makes a very attractive catalyst. In addition,
laboratory tests indicate that converters using mullite would have 45% lower
emissions than those using platinum.
The Nanostellar team, led by Dr Kyeongjae Cho, has determined that
a mineral catalyst would be a cheaper alternative.
“Our goal to move away from precious metals and replace them with
oxides that can be seen commonly in the environment has been achieved,” Cho
said.
“We’ve found new possibilities to create renewable, clean-energy
technology by designing new functional materials without being limited by the
supply of precious metals.”
The new catalyst, called Noxicat, will be developed for commercial
use and further work is planned to determine its application in fuel
cells.
Cho is professor of materials science and engineering and physics
at UT Dallas, and co-founder of Nanostellar.
Platinum, the best sponge of toxic gasses in car exhausts and the
source of most of the North West’s wealth, looks set to be replaced by a
laboratory-grown mineral.
