Reactivity of diatomics and of ethylene on zeolite-supported 13-atom platinum nanoclusters
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Date
Authors
Keppeler, Melanie
Bräuning, G.
Radhakrishnan, Shankara Gayathri
Liu, X.
Roduner, Emil
Jensen, C.
Journal Title
Journal ISSN
Volume Title
Publisher
Royal Society of Chemistry
Abstract
Monodisperse Pt clusters of 132 atoms, supported on the zeolites NaY and KL and saturated with chemisorbed hydrogen, are investigated as well-defined
model catalysts for reactions of CO, NO, O2 and ethene. CO reacts within <10 min, leading to the formation of dinuclear Pt carbonyl molecular clusters. The
similar behaviour of NO suggests an analogous reaction. In stark contrast, O2 reveals very sluggish reaction on a timescale of days although the reaction
with chemisorbed hydrogen to H2O is thermodynamically still favoured. This is ascribed to the inability of O2 to adsorb atop of Pt when all neighbouring
sites are blocked by chemisorbed hydrogen. The hydrogenation reaction of ethene yields ethane as the only product. The turnover frequency at room
temperature is somewhat lower than the one reported for the same reaction on Pt(111) single crystal surfaces or on Pt nanoparticles, but its activation
energy is double of that typically found in the other systems. This means that the reaction which has been known to be structure-insensitive becomes
structure-sensitive for catalyst clusters as small as 13 atoms. This fact is ascribed to a significantly larger binding energy of H on Pt as a consequence of the
small cluster size and the influence of the support.
Description
Keywords
Reactivity of diatomics, Model catalysts, Nanoclusters
Sustainable Development Goals
Citation
Keppeler, M, Brauning, G, Radhakrishnan, SG, Liu, X, Jensen, C & Roduner, E 2016, 'Reactivity of diatomics and of ethylene on zeolite-supported 13-atom platinum nanoclusters', Catalysis Science and Technology, vol. 6, no. 18, pp. 6814-6823