Photocatalyst for clean hydrogen and other chemicals
The journey to design an efficient plasmonic photocatalyst (with the potential to transform the chemical industry) began in the Laboratory for Nanophotonics at Rice University. Syzygy Plasmonics was formed with the express purpose of commercializing the photocatalyst technology discovered by Syzygy cofounders Professors Naomi Halas and Peter Nordlander.
Why this technology matters
Many industrial processes require chemical reactions to produce the compounds used in common everyday products that make our lives safer, easier, and more fulfilling. These processes are driven by foundational chemical reactions enabled by catalysts. The problem is that traditional catalytic reactions are driven by fossil-fuel-derived heating processes which cause greenhouse gas emissions. Only by reducing reliance on heat (combustion) can we ever hope to clean up the chemical industry. Syzygy photocatalyst technology provides a clear pathway for replacing combustion and eliminating emissions associated with powering chemical manufacturing.
Discovery of the antenna-reactor
Developing a photocatalytic process to shift our reliance away from thermal energy has been a goal for many research institutions and governments for more than 50 years. However, early semiconductor-type photocatalysts such as titanium dioxide had limited light absorption and surface chemistry profiles with subsequently low efficiencies and real-world applications. And conventional catalysts weren't an option because they were not photo-reactive.
The breakthrough came when researchers embedded a nano-particle of a traditional catalyst material into the surface of a larger light-harvesting plasmonic nanoparticle. This two-part nanoparticle structure is referred to as an antenna-reactor. This antenna-reactor concept dramatically increased photocatalytic efficiency, making commercial applications for photocatalytic processes a reality for the first time. The antenna-reactor provides more efficient capture and transfer of light energy to the reactive sites on the catalyst, effectively replacing the need for thermal energy from the combustion of fossil fuels with light. This antenna-reactor concept can be applied to develop photocatalysts for multiple chemical reactions, providing a path for replacing thermocatalysis with photocatalysis throughout the chemical value chain.
Read more about the antenna-reactor in this 2016 article published in PNAS: Heterometallic antenna−reactor complexes for photocatalysis.
Watch this short video to learn more about how we are using energy from LED lights to drive chemical reactions.
Further progress and development
In 2018, the antenna-reactor was the focus of an article in Science, where we were able to show that plasmonic catalysts reduced the overall barrier to chemical reactions. By quantifying this reduction, we gained insight into the role of hot carriers in plasmon-mediated photochemistry. This turned out to be critical in our next efforts to design various energy-efficient plasmonic photocatalysts. Read more on the Science website here Quantifying hot carrier and thermal contributions in plasmonic photocatalysis.
The potential benefits of the photocatalysis had become even more clear by 2020 when Nature published Light-driven methane dry reforming with single atomic site antenna-reactor plasmonic photocatalysts. We now understood that this technology could realistically be used to tackle the hard-to-abate industrial processes on which modern life depends. It was time to liberate the chemical industry from its reliance on thermal energy derived from burning fossil fuels.
One reactor design, multiple designer photocatalysts for different reactions
As we were finalizing our reactor design, we began developing specific designer photocatalysts to drive chemical reactions including hydrogen from ammonia, combustion-free steam methane reforming, and carbon utilization. This is where science and engineering are now combining to bring to market the world’s first commercially viable photoreactor and photocatalysts. Read more about our product roadmap on the research and development page.