Researchers at Rice University have developed a catalyst that could render steam methane reforming, or SMR, entirely emission-free by using light rather than heat to drive the reaction.

The researchers believe the work could prove to be a breakthrough for extending catalyst lifetimes. This will improve efficiencies and reduce costs for a number of industrial processes that are affected by a form of carbon buildup that can deactivate catalysts called coking.

The new copper-rhodium photocatalyst uses an antenna-reactor design. When it is exposed to a specific wavelength of light it breaks down methane and water vapor without external heating into hydrogen and carbon monoxide. The importance of this is it is a chemical industry feedstock that is not a greenhouse gas. Rice’s work also shows that the antenna-reactor technology can overcome catalyst deactivation due to oxidation and coking by employing hot carriers to remove oxygen species and carbon deposits, which effectively regenerates the catalyst with light.

The new SMR reaction pathway build off a 2011 discovery from Peter Nordlander, Rice’s Wiess Chair and Professor of Physics and Astronomy and professor of electrical and computer engineering and materials science and nanoengineering, and Naomi Halas. They are the authors on the study about the research that was published in Nature Catalysis. The study showed that the collective oscillations of electrons that occur when metal nanoparticles are exposed to light can emit “hot carriers” or high-energy electrons and holes that can be used to drive chemical reactions.

“This is one of our most impactful findings so far, because it offers an improved alternative to what is arguably the most important chemical reaction for modern society,” Norlander says in a news release.

The research was supported by Robert A. Welch Foundation (C-1220, C-1222) and the Air Force Office of Scientific Research (FA9550-15-1-0022) with the Shared Equipment Authority at Rice providing data analysis support.

“This research showcases the potential for innovative photochemistry to reshape critical industrial processes, moving us closer to an environmentally sustainable energy future,” Halas adds.

Hydrogen has been studied as it could assist with the transition to a sustainable energy ecosystem, but the chemical process responsible for more than half of the current global hydrogen production is a substantial source of greenhouse gas emissions.Hydrogen is produced in large facilities that require the gas to be transported to its point of use. Light-driven SMR allows for on-demand hydrogen generation,which researchers believe is a key benefit for use in mobility-related applications like hydrogen fueling stations or and possibly vehicles.