A surprising idea really that
iron pyrite might succeed as a catalyst.
Rare earths have been the easy route when a catalyst is needed, but as
we have seen, the demand has become ruinous to industry and the need for alternatives
are both pressing and economically valuable.
At least now the hunt is on in
earnest and plenty of molecules are prospective for this purpose. The key should be among the insolubles as
iron pyrite happens to be.
Modern modeling methods allow a
lot to be done before the actual synthesis begins. This can hopefully speed the search. Effective inexpensive catalysts are long
overdue in chemistry. We now understand
them well enough to know how to look.
A mineral way to catalysis?
by Staff Writers
Catalytic materials, which lower the energy barriers for chemical
reactions, are used in everything from the commercial production of chemicals
to catalytic converters in car engines. However, with current catalytic
materials becoming increasingly expensive, scientists are exploring viable
alternatives.
Researchers at the University
of Cambridge
In the past, sulphur was believed to be one of the most detrimental
elements for surface chemical
reactions, able to decrease dramatically the reactivity of a catalyst by
occupying (poisoning) the "active sites" on the material, but more
recently some sulphur materials (for example, molybdenum sulphides) have
actually shown interesting catalytic properties of their own.
Using state-of-the-art electronic structure calculations, researchers
led by Stephen Jenkins at the University's Department of Chemistry,
explored the potential catalytic activity of iron pyrite, the most abundant
sulphur mineral on Earth. In their study, the Cambridge
Dr Marco Sacchi, the first author on the paper, said: "Recent
European legislation has proposed increasingly strict legislative limits
on the concentration of NOx that can be emitted by vehicles; therefore the
search for new and more efficient catalysts that can capture these molecules
and transform them into innocuous gases such as nitrogen and water vapour, is
urgently relevant."
Developing new catalysts derived from inexpensive minerals, instead of
increasingly costly (and rare) precious metals, is an important area of
research that involves several groups around the world.
The next steps for the Cambridge researchers will be to investigate the
activity of pyrite surfaces for strategically important industrial reactions,
such as the manufacture of ammonia for fertilisers, the production of synthetic
hydrocarbon fuels from renewable biomass,
and the extraction of hydrogen for use in future fuel cell electric vehicles.
Dr Sacchi added: "The necessity of finding reliable alternatives
to overexploited catalytic materials - such as platinum, rhodium and gold -
will soon become unavoidable. Experimental work is
currently underway in our group, and we hope that our work will ultimately
allow us to test the potential for catalytic application of a wide range of
sulphidic and carbidic materials. In future, we aim to develop fruitful
scientific collaborations with chemical engineering groups and with industrial
partners."
The paper, "The Interaction of Iron Pyrite with Oxygen, Nitrogen
and Nitrogen Oxides: a First-Principles Study", will be published in
Physical Chemistry Chemical Physics on online 10 February 2012. (Article
citation: Phys. Chem. Chem. Phys., 2012, DOI: 10.1039/C2CP23558G.) Authors of
the work: Marco Sacchi, Martin Galbraith and Stephen Jenkins Department of
Chemistry, University
of Cambridge
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