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An Atomic‐Scale View of CO and H 2 Oxidation on a Pt/Fe 3 O 4 Model Catalyst
Author(s) -
Bliem Roland,
van der Hoeven Jessi,
Zavodny Adam,
Gamba Oscar,
Pavelec Jiri,
de Jongh Petra E.,
Schmid Michael,
Diebold Ulrike,
Parkinson Gareth S.
Publication year - 2015
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201507368
Subject(s) - catalysis , oxide , metal , scanning tunneling microscope , atomic units , cluster (spacecraft) , oxygen , chemistry , desorption , heterogeneous catalysis , iron oxide , inorganic chemistry , crystallography , materials science , nanotechnology , adsorption , physics , biochemistry , organic chemistry , quantum mechanics , computer science , programming language
Metal–support interactions are frequently invoked to explain the enhanced catalytic activity of metal nanoparticles dispersed over reducible metal oxide supports, yet the atomic‐scale mechanisms are rarely known. In this report, scanning tunneling microscopy was used to study a Pt 1‐6 /Fe 3 O 4 model catalyst exposed to CO, H 2 , O 2 , and mixtures thereof at 550 K. CO extracts lattice oxygen atoms at the cluster perimeter to form CO 2 , creating large holes in the metal oxide surface. H 2 and O 2 dissociate on the metal clusters and spill over onto the support. The former creates surface hydroxy groups, which react with the support, ultimately leading to the desorption of water, while oxygen atoms react with Fe from the bulk to create new Fe 3 O 4 (001) islands. The presence of the Pt is crucial because it catalyzes reactions that already occur on the bare iron oxide surface, but only at higher temperatures.