(see Graphic)
William Henry Perkin observed in the late 19th century that the wonders in
his Oxford garden were produced by nature at the modest temperatures of an
English summer and without the use of concentrated sulphuric acid. He knew
from his pioneering work on organic dyestuffs that chemical synthesis in
the laboratory and factory was a much harsher affair. But some areas of
modern industrial chemistry are coming to have more in common with the
gentle ways of nature than Perkin ever dreamt possible.
The building blocks in many natural chemical reactions are highly reactive
molecules called radicals which are produced from more stable entities by
the addition or removal of electrons, usually by enzymes. Vital biochemical
processes, including respiration and photosynthesis, depend on this electron
transfer. Addition and removal of electrons is also the basis of
electrochemistry, which uses electric potentials as the driving force behind
chemical reactions.
Electrochemistry was used to make molecules as long ago as the middle of the
19th century. It grew in industrial importance in the 1960s when it was used
to make raw materials for the burgeoning polymer industry. Now the
importance of electrochemistry is growing again, particularly for
carbon-based (organic) chemistry, as chemicals industries shift from making
basic chemicals in enormous quantities to smaller amounts of more
specialised chemicals, and as tougher environmental laws begin to bite.
Electrochemistry is also the basis of new methods being developed for
destroying toxic organic pollutants.
Electrochemical reduction or oxidation has several advantages over
conventional methods of making reactive chemicals. First, it works at low
temperatures. In this respect it is similar to photosynthesis,…
