Nanoscience revolusionizing Green Chemistry? ft. Julio Terra
In this episode
- What green chemistry means, and why small changes to a catalyst can make a whole chemical process greener
- Why the pharmaceutical industry produces around 90% waste for 10% product, and how Julio made a rose fragrance and amines in fewer steps
- What heterogeneous catalysis is, explained with salt and sand in water
- His path from an agricultural university near his village in Brazil, via Toronto and McGill, to a postdoc at EPFL
- How trapping reactions inside tiny pores changes the chemistry, explained with The Little Prince, and how this kept hydrogen in place long enough to use it
- His three wishes for science: more LGBTQ people, more women and more BIPOC people
Key Takeaways
- Catalysis sits in almost every chemical product, so small tweaks to a catalyst change a whole process, less energy, higher selectivity, less waste; this is the lever green chemistry pulls.
- Pharma is the worst offender (~90% waste, 10% product) because molecules need many low-yield steps, and most of that waste is solvent, which chemists routinely ignore.
- Concrete wins: making rose-oxide fragrance (multi-ton scale) via a photochemical step (light is abundant and safer than heat), and making amines in one step that reincorporates fragments that would otherwise be waste (atom economy).
- Heterogeneous catalysis (sand-in-water, not salt-in-water) lets you filter or settle out scarce, toxic metal catalysts so they don’t end up in the product.
- Confinement effect: molecules in spaces near their own size constantly hit the walls and each other and so react differently, he trapped in-situ-generated hydrogen in tiny nanospheres so it’s consumed before it escapes, and wrote a COVID-lockdown review on using confinement to make chemistry greener.
- The green-chemistry community is unusually tight-knit and welcoming, and courses/summer schools now exist where they didn’t in his undergrad; he came to chemistry wanting to teach and values science’s global, people-centred side. Three wishes: more LGBTQ, women and BIPOC people in STEM.
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About the guest
Julio Terra is a Post-doctoral Associate at EPFL in Switzerland, where he designs nanostructures with controlled composition, size and shape to make catalysts for green chemistry. In his PhD at McGill University, he trapped a catalyst inside hollow silica shells to study confined chemistry. He obtained his BSc and MSc in Chemistry in Brazil, with exchanges at the University of Toronto and McGill.
Julio Terra curated the Real Scientists Nano Twitter account (@RealSci_Nano) from April 2 to April 11 2023. Read all of Julio’s tweets from that week.
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Part of Energy & Sustainable Materials · Catalysis & green chemistry
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