The future of clean energy

7 September 2015

Dr Steve Tse is a Croucher fellow, having received his fellowship in 2013 to pursue postdoctoral research on proton exchange membranes, at the University of Chicago.

We recently caught up with Tse, and asked questions about his research with the Voth Group, and his thoughts about the future of clean technology.

Tell us about your educational background.

My research is based on statistical mechanics that provide a link between the macroscopic properties of matter and the properties of atoms and molecules that are governed by quantum mechanics. In graduate school, I worked with Professor Hans Andersen at Stanford University to develop new theories and simulation tools, rooted in statistical mechanics, for studying microscopic molecular motion in stochastic models of liquids with highly cooperative dynamics. The work has led a new scaling theory that improved the classic theory of rigid rod polymers. These abstract problems that I studied, and the training that I received in graduate school have paved the way for how I approach research problems in my career.

After graduate school, I joined Professor Gregory Voth at the University of Chicago to study the solvation and dynamics of protons. My current research on proton transport can generally be divided into two areas: first, as a theoretician, I am interested in improving the technique for studying proton transport, and the second area is concerned about more practical questions. One practical question, which I am exploring, is how proton transport in renewable energy materials, such as proton exchange fuel cell membranes, can affect the performance of an energy device. Another related practical question, which is also fundamental, is whether protons prefer going to the air-water surface like the ocean surface. The accumulation, or lack of protons at the surface, changes the surface acidity and can affect carbon dioxide absorption, which in effect is related to global warming. The air-water interface also serves as the simplest model to understand hydrophilic/hydrophobic interfaces that exist in fuel cell membranes.

Tell us about your research into renewable energy- proton transfer in proton exchange membranes.

Proton exchange membranes (PEMs) are complicated materials whose exact mesoscopic structures are sometimes still under debate. Furthermore, proton transfer reactions, even in “simple” water, are very challenging to study on computers. When we combine these two problems together, i.e. studying proton transfer in PEMs, we have a new class of exceedingly difficult, but important, problems. One reason why these problems are so difficult to study is that one should use quantum mechanics, instead of classical mechanics, to capture the essential physics and chemistry for such systems. However, quantum calculations are computationally expensive, and this means the size and time scales that can be probed in these systems are limited. Therefore, a significant portion of my research is about how to study these problems more accurately and efficiently. With our successfully developed method and model, we can now answer questions such as how proton transfer and also conductivity are affected by water in the membranes and through what mechanisms. Such fundamental studies that reveal basic properties of these systems and connect this behaviour to desired material performance are fertile ground for advancing these technologies.

What benefits will be brought about by the replacement of alkaline fuel cell technology with proton exchange membrane fuel cells?

The alkaline fuel cell (AFC) is one of the cheapest and also most developed fuel cell technologies. NASA actually used AFCs in the Apollo missions and space shuttles. The electrolyte is at the heart of a fuel cell. In an AFC, the electrolyte is a solution that can have leakage problems and react with atmospheric carbon dioxide that forms carbonate and deteriorates the electrodes. There are no such problems in the proton exchange membrane fuel cells (PEMFCs) because its electrolyte is a solid polymer membrane and inert to carbon dioxide. Such advantages make PEMFCs very suitable for transport applications. Indeed, Toyota is one of the first auto companies that has built cars utilising PEMFCs for sales in 2015.

What, in your opinion, is the future of clean technology?

I believe the future of clean energy relies not only on one, but multiple technologies. For instance, the fuel cell technology that I study will be excellent for powering portable devices, because the fuel cells are portable. However, to power our homes, using solar or wind power is more suitable. Furthermore, the geographic locations also play an important role. For example, it makes sense to rely on solar power in sunnier places, such as California or Colorado. To resolve the global energy problems, we truly need scientists and engineers from different fields to attack the problems at different angles.

Tse starts a new post next month as assistant professor at the chemistry department of the Chinese University of Hong Kong.

Dr Steve Tse received his bachelor’s degree in chemistry, computer science, and mathematics in 2006 from Towson University, Maryland. Steve then studied under Professor Hans C. Andersen for his Ph.D. in chemical physics at Stanford University and he graduated in June 2011. Before he joined the University of Chicago’s Voth Group as a postdoctoral scholar in August 2012, he was based in Colorado, working on a joint project with Colorado School of Mines, National Renewable Energy Laboratory, and the University of Chicago to study proton exchange membranes.

To view Dr Steve Tse’s personal Croucher profile, please click here.