Margarine, petrol and fertiliser appear to have little in common. But
in the chemical processes that yield these disparate products, molecules
must be persuaded to take part in a sequence of well-drilled moves that
would be complex and action-packed enough to satisfy the choreographer of
a West End musical. This show even has its own stars – not the atoms and
molecules that rearrange themselves to form the end product, but small amounts
of metal, catalysts that keep the molecules in step as chemical bonds break
and re-form at lightning speed. Without these catalysts, the reactions that
the chemicals industry relies on would be impractically slow.
Scientists are even making ‘movies’ of the molecular dance on the surface
of catalysts. Their work will never reach the big screen; the pictures look
more like a sequence of contour maps than close-ups of atoms. But it goes
a long way towards creating a picture of some of the world’s most valuable
chemical reactions. Even more important, these techniques could be the key
to designing the catalysts of the future.
Anyone who has ever experienced the stench of bad eggs as a car with
a cold engine drives off will know that the catalytic converters used to
clean up car exhausts are far from perfect. The same goes for the other
industrial catalysts, despite the billions of dollars that have been spent
on developing and manufacturing them. But chemists developing new catalysts
still work by trial and error. The problem is that to design the perfect
catalyst it is necessary to know exactly how atoms and molecules behave
on a surface. To find out,…
