Cottrell Scholar Awards - 2016
A New Handle in Solar-to-Fuel Light Harvesting: Creating Protons Where They are Most Needed
Storing the energy from sunlight in chemical bonds is a world-wide scientific and technological challenge. If researchers are able to successfully meet this challenge, it may result in technologies that can generate fuels for vehicles and aircraft directly from sunlight using abundant ingredients such as water and carbon dioxide.
Jahan Dawlaty, assistant professor of chemistry, University of California, is attempting to develop a more effective catalyst – basically a molecular factory -- for producing these chemical bonds.
To keep the fuel production rate high, a catalyst must receive an ample supply of electrons and protons. “But quite often, production runs slow just because the proton supply is short and cannot keep up,” he says.
To overcome this problem, Dawlaty theorizes that light itself can be used to drive the release of protons near the surface of a catalyst. His group will use “photoacids” as a first step to implementing this plan. Photoacids are molecules that release a proton upon light excitation.
They will be tethered near a catalytic surface and, when excited by light, it is hoped they will release an abundant supply of protons. Dawlaty’s research will evaluate the details of maintaining and driving the proton supply line using light.
He also hopes to place photoacids in proton-conducting polymers (long-chain molecules) to create something analogous to an electric current, but with protons rather than electrons. “To my knowledge, this approach is an entirely new conceptin catalysis, and holds significant potential for redox reactions,” Dawlaty said. (A redox reaction involves the transfer of electrons between atoms or molecules.)
For the education component of the Cottrell Scholar Award, Dawlaty plans to modernize courses on thermodynamics and kinetics from their 19th-century origins, which were concerned with issues like improving the efficiency of steam engines. He will create learning modules and concept maps to connect these older concepts to contemporary challenges and technologies, such as harvesting sunlight, purifying drinking water and understanding global climate change.