Berlin 2018 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 78: Poster: Surface Dynamics - Reactions, Elementary Processes and Phase Transitions
O 78.4: Poster
Mittwoch, 14. März 2018, 18:15–20:30, Poster A
Segregation Study of Size-Selected Bimetallic Nickel-Cobalt Nanoparticles for Partial Oxidation of Methane — •Peter Franz Zajac1, Ioannis Zegkinoglou1, Lukas Pielsticker1, and Beatriz Roldan Cuenya1,2 — 1Department of Physics, Ruhr University Bochum, 44780 Bochum, Germany — 2Department of Interface Science, Fritz-Haber Institute of the Max Planck Society, Berlin 14195, Germany
Alloying and segregation phenomena in bimetallic nanoparticle catalysts crucially affect their elemental surface composition and are often responsible for synergistic effects which enhance their catalytic performance in comparison to their monometallic counterparts. We used in situ X-ray photoelectron spectroscopy, both in ultra-high vacuum and under near-ambient pressure conditions (NAP-XPS), in combination with atomic force microscopy (AFM), to investigate the morphological stability, chemical state and surface composition of size-selected bimetallic nickel-cobalt nanoparticles supported on silicon dioxide substrates as a function of temperature and gas environment for the catalytic partial oxidation of methane (CPOM). The studies demonstrated the remarkable stability of surface cobalt oxide species under reducing conditions and indicate that pretreatment of the nanocatalysts by plasma etching or annealing can help tune their catalytic properties.