Cottrell College Science Awards - 2015
In-situ Study of Metal and Metal-oxide Gas Phase Catalysts Using Surface X-ray Scattering
A catalyst is a substance that, due to its presence, increases the rate of a chemical reaction and is not itself consumed in that reaction. Catalysts are very important to industry, and yet we don’t know as much as we should about how they work.
We do know, however, that in metal and metal oxide catalysts, which are important to fuel cells, batteries and catalytic converters, a thin layer or two of atoms on the surface of these materials very often determines effectiveness.
Michael S. Pierce, assistant professor of physics at Rochester Institute of Technology, has received a Cottrell College Science Award from Research Corporation for Science Advancement to better understand the surface characteristics of metal and metal oxide catalysts in “real world” conditions. Until recently, these phenomena could only be easily studied in ultra-high vacuum conditions.
“New extensions of X-ray scattering techniques can examine surface reactions in harsh environments,” Pierce points out, adding that he and his students will use X-ray photon correlation spectroscopy (XPCS) to study important catalysts such as gold (Au) and titanium dioxide (TiO2). The extension of XPCS to atomic-scale surfaces is relatively new, utilizing coherent X-ray beams to produce unique speckle patterns that reveal atomic-scale processes as the surface structure evolves. Such techniques are just possible with the latest upgrades to synchrotron based X-ray sources.
Pierce will try to understand how particle size and other factors affect catalysis of chemical reactions, particularly those related to energy production and sustainability. “Answers to such questions can, we hope, lead to a better understanding of catalysts with real-world applications and benefit,” he said.