ADRIAN FLORIDO, HOST:
To create the molecules we want and need, like to help us grow food or make fuel, we rely on chemical reactions. But manipulating molecules often demands lots of effort and energy. One scientist may have a brighter approach. NPR's Ari Daniel says she and her team are learning to control chemistry with light.
ARI DANIEL, BYLINE: Jen Dionne grew up with "The X-Files."
JEN DIONNE: It was really cool to watch two people - a special agent and a physician - work together as a team to solve mysteries.
DANIEL: This was preinternet, so to further steep herself in the paranormal, Dionne went to the bookstore.
DIONNE: Alphabetically, the paranormal section was right next to physics.
DANIEL: She began devouring those books as well, which revealed to her how the science of light could explain things she'd seen in the real world, like how a glass of water can split a sunbeam and scatter rainbows across a room.
DIONNE: That was just very beautiful and mysterious to me.
DANIEL: This love of light stayed with Dionne. She began considering how sunlight has shaped the chemistry of our planet - think photosynthesis or the proteins in our eyes - and she came to wonder whether she could harness light somehow.
DIONNE: Basically, do what nature does so well - creating valuable chemicals sustainably.
DANIEL: For centuries, people have taken a blunt-force approach to making the molecules and materials they want, using lots of energy to crank the heat and pressure to force atoms together or break them apart.
DIONNE: You can think about kind of temperature and pressure as a chemical sledgehammer.
DANIEL: Dionne wanted to try something rather different, using light as a kind of chemical scalpel.
DIONNE: A tool that allows you to very precisely control what atoms and molecules are doing to create exactly the product you want and very little of the products you don't want.
UNIDENTIFIED PERSON: Thank you.
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DANIEL: Dionne, who's now at Stanford University, escorts me into her lab space. Lin Yuan, one of her researchers, shuts the lights off.
LIN YUAN: So I'm going to show you a quick demo.
DANIEL: He's converting ethane into ethylene, a gas that's used to make all sorts of plastics, says Dionne.
DIONNE: But that is a process that usually requires hundreds if not thousands of degrees and comes from burning fossil fuels.
DANIEL: Yuan demonstrates that traditional approach by firing up the reaction in a small metal and glass chamber. A computer displays the resulting products. There's some ethylene, of course, but there's a whole lot of waste, including greenhouse gases like methane and CO2.
DIONNE: You're literally just almost obliterating everything and then just getting a small fraction of the product that really matters.
DANIEL: The story is wholly different with light, which the researchers deliver with a low-powered laser. Here's how it works. Dionne uses nanoparticles - metal atoms arranged in a particular shape, like a prism. When she illuminates the particles, the laser light concentrates at specific places in that atomic lattice, at the tips, say, or along the edges. That pushes the electrons of the metal around in just the right way so they can help make or break bonds, precisely forging the desired molecule.
It's a technique that Dionne and one of her graduate students, Amy McKeown-Green, are also applying to fertilizer, which is made by converting nitrogen gas into ammonia, a chemical reaction responsible for about 2% of all global greenhouse gas emissions.
AMY MCKEOWN-GREEN: Roughly 50% of the nitrogen atoms in your body and in my body came from food that was growing using synthesized fertilizer.
DANIEL: Assuming the light that Dionne's using is powered by renewables, she and her team can run the same reaction at room temperature and under normal pressure without any net emissions.
DIONNE: That is exactly what we are now trying to scale up.
DANIEL: Which Dionne says may only be a few years off. When Dionne was watching "The X-Files" as a girl, she never could have imagined her current field of inquiry.
DIONNE: I thought initially the only type of researcher you could be was one that researched the paranormal and aliens.
DANIEL: Now Dionne's studying her own set of mysteries.
DIONNE: In many ways, trying to see what can't easily be seen.
DANIEL: By shining a light on a new way of doing chemistry. Ari Daniel, NPR News.
(SOUNDBITE OF POST MALONE SONG, "CHEMICAL") Transcript provided by NPR, Copyright NPR.
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