Catalothermionic Solid State Electric Generator with Nonadiabatic Functionality

University Of Illinois At Chicago, Chicago IL

Investigators

Abstract

1033290 Karpov Existing sustainable (non-fossil and non-nuclear) technologies of electric power generation can be grouped into two broad categories. The first incorporates systems and devices for the utilization of mechanical energy and conversion into electricity (wind, tidal and geothermal turbines), and the second covers the solid state electric generators designed for the conversion of solar, chemical and thermal energy directly into electricity without resorting to mechanics. These three: fuel cells, solar cells and thermoelectric generators have been the subject of intensive research. However. the high cost of solar cells and limited efficiency and lifetime of fuel cells constrain their massive implementation. While the thermoelectric generators demonstrate better lifetimes, they do not provide satisfactory efficiency and energy density in order to successfully compete with the traditional portable sources of power. PI Eduard Karpov of the University of Illinois Chicago poses the question whether there are other useful mechanisms that have been overlooked thus far in sustainable energy research. Karpov proposes a new device called a catalothermionic generator as one such possibility. These generators will incorporate the nonadiabatic energy conversion processes similar to those in solar cells, but utilize catalytic oxidation of hydrogen to water on the device surface as the energy source. The catalytic reaction leads to the chemically induced excitation of hot electrons in the catalytic metal-semiconductor nanostructures, followed by the ballistic transport of these electrons across the metal nanolayer and over the Schottky barrier. The catalothermionic generator device is comprised of a nanofilm of palladium metal as cathode, an n-type semiconductor such as SiC as the anode and an ohmic back contact and external circuit to deliver electricity to perform the work. The reaction of H2 oxidation is catalyzed at the nanofilm to generate the hot electrons. In the final stages of the work, the PI plans to demonstrate the reverse system as well. This is one in which hot holes are generated instead of hot electrons, and a p-type semiconductor material is used. The project explores the possibility and practical feasibility of a novel type of higher efficiency, chemically driven solid state electric generators. The technical impact of an improved method of energy conversion and delivery is self-apparent. The PI is opening the area of chemovoltaics, analogous to photovoltaics. Impacts will be felt in heterogeneous catalysis, surface science, nanomaterial and nanocatalysis research and sustainable energy science. For the educational and outreach aspects, this is the sort of exciting project that inspires young investigators to join up and pursue the project and science and engineering. It is also one that can be translated, although not easily, into a popular version which might help educate the more general populace as to the limits in technologies, and how science can develop new approaches to developing solutions.