Heath Kersell became interested in science as a way to uncover the fundamental building blocks for technologies that improve people’s lives. As an ALS postdoc, he’s researching catalysis and putting together mentorship circles for his fellow postdocs.
What do you research?
During my PhD, I realized that it’s important not just to understand the physics of a system but also to understand how molecular systems are interacting chemically with the surfaces they are on. So, I came to work with Miquel Salmeron in the Materials Sciences Division for my postdoc, where I used some of the skills that I developed during my PhD. I also learned about heterogeneous catalysis and how, in a chemical reaction, the reactants involved can actually change a catalyst’s structure. Those structural changes can create new sites at catalyst surfaces and open up new reaction pathways, so it’s important to see what’s happening to the nanoscale structure and chemistry of a sample under reaction conditions.
During my work with Miquel, I had beamtime at the ALS and met Slavo Nemsak, whose group I then joined to get in on the development of a new technique. It combines ambient-pressure x-ray photoelectron spectroscopy (APXPS) with grazing-incidence x-ray scattering to simultaneously measure the structure and chemistry of samples in reaction conditions. The goal is to get a picture of how those properties are correlated and how they can be responsible for chemical activity. So that’s how I came to the ALS—to develop a technique that would give us deeper insights into the kind of phenomena that I was studying.
What are your goals for this technique?
When I started working on catalysis, I used scanning tunneling microscopy a lot. It’s great for measuring nanoscale surface structures, but it doesn’t easily tell you the chemical or elemental identity of those structures. With grazing-incidence x-ray scattering, we can measure surface structure, and by simultaneously using APXPS, we can correlate that information with the chemistry happening at the surface. What’s really powerful is that, once something changes in the chemistry, we can immediately measure the structure in the same experiment. On top of that, using grazing-incidence x-ray scattering potentially gives access to additional techniques beyond traditional structural or spectral measurements. We can get a picture of the spatial distribution of elemental or chemical species or of the time dependence of structural transformations.
Recently, using capabilities at the Molecular Foundry, we put patterned gold dots on a reducible substrate to model strong metal-support interactions. When noble metal nanoparticles, like gold, are used for a catalytic reaction, they can interact strongly with reducible surfaces, and that can change the way the nanoparticles do catalysis. Our new technique is great for understanding structural and chemical changes in nanoparticle systems like these.
Have you always been interested in this field?
It’s kind of a natural extension of my previous work and also something I was interested in for a long time. What got me into science was that I always wanted to work on discovering fundamental processes that could be used for technologies that improve people’s lives. In catalysis, you can really do that. You can study reactions that are used for energy storage and transfer. I did my PhD at Ohio University and spent two years at Argonne National Lab, where I demonstrated a method for correlating structure and chemical compositions for samples, both at the single nanometer range. And our new technique at the ALS allows us to do something like that but also in gas environments and reaction environments, so it’s like a complementary method to something that I had done in the past.
How are you involved in inclusion, diversity, equity, and accountability (IDEA) at the ALS?
I’m part of the ALS Education and Communication Task Force and the Career and Professional Development Task Force, and I really like that those helped me learn about IDEA concepts. I also like that it gave me the opportunity to contribute to the development and implementation of IDEA concepts around the ALS community. It’d be great to see more postdocs involved.
I’m also working on postdoc mentoring circles with ALS staff scientist Padraic Shafer. A strong predictor of success in professional development is good mentorship, but for postdocs, your experience is often singular. Postdocs have unique projects, they come from all kinds of backgrounds and have all kinds of things going on in their personal lives, and have a range of career goals, but they’re often predominantly interacting with just their research group and PI. It’s unusual for the limited number of people you interact with to be able to give the guidance that you need to move toward the variety of careers that you might be interested in. So, we looked into the possible mechanisms for mentorship for postdocs.
We came across mentorship circles of small groups of peers. Some of the mentors or leaders guide discussion on a topic the group is interested in developing, like leadership, or proposal writing, or project planning. The group helps each other grow and share experiences. We’re now recruiting members.
What do you like to do in your free time?
What’s free time?! I relax by playing with my dog and hanging out with my wife, and these days that’s all my free time.