05-17 solid acid fuel cell

[Image above] Northwestern University professor Sossina Haile, right, and her previous Ph.D. student Calum R. I. Chisholm, left, reenact their journey to developing and commercializing the solid acid fuel cell in a video by MilliporeSigma/Sigma-Aldrich. Credit: MilliporeSigma/Sigma-Aldrich

Throughout all the Bulletins this year, energy has been a consistent theme. That is because the topic is top of mind for manufacturers who are witnessing the susceptibility of our current energy infrastructure to climate-related and geopolitical events.

Hydrogen is one energy carrier that is emerging as a keystone of next-generation energy plans. Hydrogen fuel only yields water when burned, thus avoiding the release of greenhouse gases, plus has a much higher specific energy density than fossil fuels, and so less is needed to achieve the same energy output.

There are many challenges to realizing a hydrogen economy, however, that occur all along the supply chain. For example, even though hydrogen has a high specific energy density, its volumetric energy density is very low. As such, storing or using hydrogen at atmospheric pressure and temperature requires a substantial amount of space.

Hydrogen takes up less space if it is compressed or liquified, but doing so is a technological challenge, especially if the compression/liquification system is meant to be transportable. Instead, converting hydrogen into ammonia (NH3) allows for easier liquification and storage, and thereby easier transportation.

Yet the ammonia-based approach to hydrogen transportation comes with its own drawback—extracting hydrogen from the ammonia once it reaches its destination.

Solid acid fuel cells could be an answer to this obstacle.

Solid acid fuel cells are mid-temperature range fuel cells (~250°C) that use cesium dihydrogen phosphate as the electrolyte. They are the brainchild of Sossina Haile, ACerS Fellow and Walter P. Murphy Professor of Materials Science and Engineering at Northwestern University.

Haile developed solid acid fuel cells in the late 1990s when she was a professor at the California Institute of Technology. When her first Ph.D. student, Calum R. I. Chisholm, graduated, he decided to start a company to commercialize the technology.

Haile and Chisholm initially planned to use the fuel cell to convert hydrogen into electricity, but when the 2008 economic crisis hit, funding for green energy technology dried up. Instead, they secured contracts to use their technology to convert fossil fuels, and this funding solution served as their lifeline for more than a decade.

As attention to and funding for hydrogen technologies started ramping up again in recent years, Haile realized their fuel cell could be a perfect solution to the hydrogen-from-ammonia extraction problem.

“Ammonia is similar to a dirty fuel because it poisons the catalyst. Our fuel cell can handle poisons. It’s tolerant,” she says in an interview with MilliporeSigma/Sigma-Aldrich.

Running their fuel cell in reverse, with ammonia and electricity as the inputs, Haile and Chisholm were able to produce pure hydrogen.

Chisholm is working to partner with companies to commercialize this application through his startup SAFCell. Interested parties looking to partner with SAFCell can contact the company through this webpage.

Haile and Chisholm’s 20-year journey to realizing the solid acid fuel cell’s potential was showcased in a video by MilliporeSigma/Sigma-Aldrich as part of its “Next Great Impossible” initiative. View the video below, and learn more about Haile’s work with fuel cells and green energy technology in her Ceramic Tech Chat podcast episode.

Credit: MilliporeSigma/Sigma-Aldrich