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Single‐Site vs. Cluster Catalysis in High Temperature Oxidations
Author(s) -
Serna Pedro,
RodríguezFernández Aida,
Yacob Sara,
Kliewer Christine,
Moliner Manuel,
Corma Avelino
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202102339
Subject(s) - chemistry , catalysis , dissociation (chemistry) , cluster (spacecraft) , metal , crystallography , molecule , fragmentation (computing) , heterogeneous catalysis , photochemistry , organic chemistry , computer science , programming language , operating system
The behavior of single Pt atoms and small Pt clusters was investigated for high‐temperature oxidations. The high stability of these molecular sites in CHA is a key to intrinsic structure–performance descriptions of elemental steps such as O 2 dissociation, and subsequent oxidation catalysis. Subtle changes in the atomic structure of Pt are responsible for drastic changes in performance driven by specific gas/metal/support interactions. Whereas single Pt atoms and Pt clusters (> ca. 1 nm) are unable to activate, scramble, and desorb two O 2 molecules at moderate T (200 °C), clusters <1 nm do so catalytically, but undergo oxidative fragmentation. Oxidation of alkanes at high T is attributed to stable single Pt atoms, and the C‐H cleavage is inferred to be rate‐determining and less sensitive to changes in metal nuclearity compared to its effect on O 2 scrambling. In contrast, when combustion involves CO, catalysis is dominated by metal clusters, not single Pt atoms.