Boosting Green Energy One Reaction at a Time

By Pranoti Kshirsagar /

Rebecca Pittkowski makes new materials to act as catalysts for making hydrogen and converting it back into energy, using hydrogen as a green energy carrier. She synthesises the materials, characterises them with a lot of X-rays, and tests whether they make a better catalyst for a fuel cell car or an electrolyser.

About the guest

Rebecca Pittkowski was a postdoctoral researcher at the University of Copenhagen when we recorded this episode in 2022. She now leads the Nanoparticles in Electrocatalysis group as an assistant professor in the Department of Chemistry at the University of Copenhagen. Her group makes metal and oxide nanoparticles for water electrolysis and fuel cells, and studies them with synchrotron X-ray techniques.

Rebecca Pittkowski curated the Real Scientists Nano Twitter account (@RealSci_Nano) from October 3 to October 8 2022. Read all of Rebecca’s tweets from that week.

Key highlights in this episode

  • 02:51 Catalysts for hydrogen, both ways. Rebecca makes new nanoparticle catalysts for electrolysers, which make hydrogen, and for fuel cells, which turn it back into electricity.
  • 08:26 From wind turbine to exhaust pipe. Green electricity splits water into hydrogen, the hydrogen is stored in a pressurised tank, and a fuel cell car recombines it with oxygen. Only water comes out.
  • 10:39 A physics teacher at 15. A lesson on fuel cell cars started it all, followed by chemistry in Dresden, a PhD in Prague, a short stay in Switzerland, and then Copenhagen.
  • 16:23 Watching atoms rearrange. Synchrotron X-rays millions of times more intense than a hospital X-ray reveal how nanoparticles change while the catalyst works, not just before and after.
  • 25:11 Three wishes. Recognition for the hours researchers put in, less weight on paper counts when one synchrotron experiment takes nine months to schedule, and steady funding for fundamental research.
Boosting Green Energy One Reaction at a Time
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Why it matters

The material an electrode is made of decides how much current you need and how much hydrogen you get out, so the aim is to make the process as efficient as possible. That’s why Rebecca puts catalyst nanoparticles on her electrodes, and why she wants to see them while they work, not just before and after. Synchrotron X-rays let her look into the reaction environment without changing it, and see whether the particles become more ordered, more disordered, or lose an active component. The catch is time: beam time can take nine months to come through, and one project two to three years to publish, which is why she argues paper counts shouldn’t be the measure of a scientist.

Terms explained

In the guest’s own words, with a link to the moment they explain it.

  • Anode and cathode: the anode is where oxidation happens and the cathode is where reduction happens. Rebecca’s memory trick: anode and oxidation both start with vowels, cathode and reduction with consonants. (Rebecca at 05:43)
  • Electrolyser vs fuel cell: an electrolyser uses green electricity to make hydrogen from water; a fuel cell recombines hydrogen and oxygen into water and releases the electricity again. (Rebecca at 08:26)
  • Synchrotron: a huge ring where electrons race around at very high speeds and give off X-rays a couple of million times more intense than a hospital X-ray source. (Rebecca at 16:44)
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Part of Energy & Sustainable Materials · Catalysis & green chemistry

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