Falling Walls: Modern chemistry turns lead into gold

Today I'll be writing a series of blogposts from the Falling Walls conference in Berlin. Each speaker is invited to discuss the ideas, inventions, and discoveries they believe will break down walls in their field.

Paul Chirik: How Modern Alchemy Can Lead to Inexpensive and Clean Technology

Professor of chemistry Paul Chirik is on a mission to turn lead into gold. Or, to be more precise, to make lead act like gold. Precious metals are instrumental to some of the most widespread and important chemical processes in our world, such as the osmium needed to synthesise fertiliser (so valuable that BASF bought up the entire world's stock at one point), and the platinum needed to make jeans bendable, shoes sturdy, and envelopes sticky. The problem is that precious metals tend to be, well, precious. Not only that, but turbulent markets and rampant speculation cause huge fluctuations in their price, impacting on the products that depend on their use as catalysts.

Precious metals tend to operate in the realms of two electron transfers, while "base" metals only operate a single electron transfer. Two electrons good in this case; single-electron transfer is responsible for all the chemistry you hate, like the free radicals in your body and the rust in your car. To get around this problem, nature engineered complex electron transport chains carried out by enzymes to produce the molecules it needs without relying on the rarer elements. Chrik is following in these footsteps, developing ways to get cheap metals like iron work like platinum, replacing the more expensive of the two in common industrial reactions.

The technique offers huge advances for sustainable chemistry. A molecule Chirik developed, when added in 1% solution to herbicide, forced it to spread over leaves instead of forming droplets. This meant 90% less was needed to treat the same area! It's not always simple of course - a replacement envelope glue designed by Chirik was rejected because nobody wanted to lick a black gumming strip (a more appeasing colour was developed).