PI: Oehrlein, Gottlieb S. / Bruggeman, Peter J. Institution: University of Maryland College Park / University of Minnesota-Twin Cities
The proposed collaborative research project aims at using a well-characterized atmospheric-pressure plasma source to enable well-controlled interactions of the plasma with earth-abundant catalysts. The activations of catalysts using plasmas holds great promise for increasing the efficiency of catalytic systems with potential applications in a broad spectrum industries, including chemical and materials synthesis, environmental remediation, and energy generation. The overriding goal of the proposed project is to investigate the underlying mechanisms that are responsible for the synergistic effects of plasma with catalysts. The plan is to correlate the magnitude of the plasma catalytic synergistic effect(s) with incident reactive species fluxes, along with changes in catalyst surface properties, and surface electronic structure. A careful systematic comparison of the different catalysts may elucidate the microscopic origins of the synergistic effect and explore potential plasma activation of thermally inactive catalysts. The project may lead to better understanding of the requirements for plasma conditions and catalysts to fully exploit the synergistic potential of plasma-catalyst systems.
A mechanistic study is proposed that is aimed at providing atomistic insights to unravel the key mechanisms responsible for the synergistic effect(s) during plasma-catalyst interactions. Iron, nickel, cobalt, and copper supported catalysts (on alumina and silica supports) will be employed in this study. These catalysts vary strongly in thermal catalytic activities due to different electronic structure and surface-catalytic mechanisms. The investigation will be focused on studying atomistic surface modifications of the catalysts for the oxygen/methane model system as the plasma-surface interaction conditions are changed. This will include the impact of these surface changes on the products formed and their formation rates. Gas phase characterization will be achieved by molecular beam mass spectrometry and two-photon laser induced fluorescence. Surface characterization will include ellipsometry, ultra-violet and x-ray induced photoemission spectroscopy coupled with thermal desorption, and Fourier transform infrared spectroscopy. The proposed approach has the potential to make transformative changes to the current state-of-the-art by enabling a mechanistically informed design of catalysts ideally suited for plasma-catalyst synergies. In addition to training graduate and undergraduate students, the investigators plan to develop course material on plasma-catalysis and an interactive lecture for middle school students.
