Strong metal support interaction on Co / niobia model catalysts
نویسندگان
چکیده
Cobalt was deposited by physical vapor deposition onto thin well-ordered niobia films in order to model niobia supported Co catalysts. Adsorption of CO on the Co/niobia surfaces was studied by temperature programmed desorption and infrared reflection absorption spectroscopy. Structural characterization was performed by photoelectron spectroscopy and scanning tunneling microscopy. Cobalt was found to wet the niobia film and be partially oxidized at 300 K in contrast to Co deposited on thin alumina films, where three-dimensional metal particles are stable up to 600 K. The combined results clearly indicate a strong interaction of Co with the niobia surface including Co migration into the film, which may have implications for the effects of niobia observed in real catalysts.
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